Bibliography

Computus, computistics

Results (79)
Bauer, Bernhard, Gloss-ViBe: a digital edition of the Vienna Bede (beta version), Online: Universität Graz, 2023–present. URL: <https://gams.uni-graz.at/context:glossvibe>
Bisagni, Jacopo, “La littérature computistique irlandaise dans la Bretagne du haut Moyen Âge: nouvelles découvertes et nouvelles perspectives”, Britannia Monastica 20 (2019): 241–285.
Warntjes, Immo, and Dáibhí Ó Cróinín (eds), Late antique calendrical thought and its reception in the early Middle Ages: proceedings from the 3rd International Conference on the Science of Computus in Ireland and Europe, Galway, 16-18 July, 2010, Studia Traditionis Theologiae, 26, Turnhout: Brepols, 2017.
abstract:
Late antique and early medieval science is commonly defined by the quadrivium, the four subjects of the seven liberal arts relating to natural science: astronomy, geometry, arithmetic, and music. The seven-fold division of learning was designed in Late Antiquity by authors such as Martianus Capella, and these authors were studied intensively from the Carolingian age onwards. Because these subjects still have currency today, this leads to the anachronistic view that the artes dominated intellectual thought in Late Antiquity and the early Middle Ages. Quite the contrary, the artes were an idealized curriculum with limited application in practice. Certainly, the artes do not help in our understanding of the intellectual endeavour between the early fifth and the late eighth centuries. This period was dominated by computus, a calendrical science with the calculation of Easter at its core. Only computus provides a traceable continuation of scientific thought from Late Antiquity to the early Middle Ages. The key questions were the mathematical modeling of the course of the sun through the zodiac (the Julian calendar) and of the moon phases (in various lunar calendars). This volume highlights key episodes in the transmission of calendrical ideas in this crucial period, and therewith helps explaining the transformation of intellectual culture into its new medieval Christian setting.
Smyth, Marina, “Once in four: the leap year in early medieval thought”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Late antique calendrical thought and its reception in the early Middle Ages: proceedings from the 3rd International Conference on the Science of Computus in Ireland and Europe, Galway, 16-18 July, 2010, 26, Turnhout: Brepols, 2017. 229–264.
abstract:
A survey of early medieval computistical works into the early Carolingian period reveals a number of interesting and unexpected themes on the subject of the leap year. Representative examples are presented in this paper. It was common knowledge that Julius Caesar, in order to keep the calendar aligned with the seasons, had introduced the practice of inserting an additional day in February every four years, so that the date we would call 24 February occurred twice in that fourth ‘bissextile’ year. There was uncertainty as to why this additional day was called bissextus. More curiously, there were two schools of thought on the duration of the bissextus: was it a 24-hour day or a 12-hour day? The more scientifically inclined understood that the leap-year day was necessary because the solar year is a quarter of a day, a quadrans, longer than the 365 days of a normal calendar year. From that perspective, it followed that each year contributed a 6-hour quadrans toward the bissextus. There was, however, a long tradition, which was imported into Britain and Ireland, that the annual contribution to the bissextus was a 3-hour quadrans. Some of the justifications, implications and consequences of this erroneous belief are examined, and it is noted that these are mostly found in texts with insular connections.
Bauer, Bernhard, “New and corrected MS readings of the Old Irish glosses in the Vienna Bede”, Ériu 67 (2017): 29–48.
abstract:

This paper offers new readings and translations of the Old Irish glosses on the fragment of Bede's De Temporum Ratione found in the Austrian National Library Codex 15298 (olim Suppl. 2698) in Vienna. In addition to the updated readings, a newly found gloss is discussed at the end of the paper.

Cuppo, Luciana, “Felix of Squillace and the Dionysiac computus II: Rome, Gaul, and the Insular world”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Late antique calendrical thought and its reception in the early Middle Ages: proceedings from the 3rd International Conference on the Science of Computus in Ireland and Europe, Galway, 16-18 July, 2010, 26, Turnhout: Brepols, 2017. 138–181.
abstract:
The dissemination of the Dionysiac computus in Rome and in Gaul did not happen in a vacuum, but found a strong competitor in the well-entrenched Victorian computus. The first part of the paper considers such opposition on the basis of three manuscript witnesses: Reg. lat. 2077 and Vat. lat. 1548 of the Vatican Library, and MS 645 of the Burgerbibliothek at Bern.

The second part of the paper considers the dissemination of the Dionysiac computus in the insular world. The main witness is MS Digby 63 of the Bodleian Library, Oxford. Written in its present from in AD 867, the manuscript includes various blocks of computistical material derived from earlier sources. They include a dossier with the letters of Dionysius Exiguus and others on the computation of Easter. The dossier ends with the prologue and preface to the cycles of Felix of Squillace (AD 616).

Certain palaeographical traits betray the Roman provenance of the Dionysiac dossier. While it is not possible to establish a definite date for the arrival of the Dionysiac collection in England, there is a strong possibility that the dossier was sent from Rome in the time of Pope Vitalian (AD 672-76) in the context of his support for the Dionysiac computus and its adoption in Rome.
Ó Cróinín, Dáibhí, “Archbishop James Ussher (1581–1656) and the history of the Easter controversy”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Late antique calendrical thought and its reception in the early Middle Ages: proceedings from the 3rd International Conference on the Science of Computus in Ireland and Europe, Galway, 16-18 July, 2010, 26, Turnhout: Brepols, 2017. 309–351.
abstract:
Archbishop James Ussher is probably best known for his reckoning of the date of the creation of the world (at the beginning of the night preceeding 23 October 4004 BC). However, his calculations were all based on a meticulous study of the Old Testament and other early Christian and non-Christian chronographical writings. This paper announces the discovery of a previously-unnoticed Oxford manuscript that lists the impressive array of patristic and post-patristic writings on the subject of the early Easter controversy that he accumulated for his researches.
Steinová, Evina, “Technical signs in early medieval manuscripts copied in Irish minuscule”, in: Marieke Teeuwen, and Irene van Renswoude (eds), The annotated book in the early middle ages: practices of reading and writing, Turnhout: Brepols, 2017. 37–85.
Ohashi, Masako, “The ‘real’ addressee(s) of Bede’s Letter to Wicthed”, in: Pádraic Moran, and Immo Warntjes (eds), Early medieval Ireland and Europe: chronology, contacts, scholarship. A Festschrift for Dáibhí Ó Cróinín, 14, Turnhout: Brepols, 2015. 119–135.
abstract:
Bede’s letter ‘On the vernal equinox, after Anatolius’ was written between AD 725 and 731. The letter is addressed to his friend Wicthed, but the study of both the letter and the Historia ecclesiastica implies that Bede had a different readership in his mind. It is argued in this article that the ‘real’ addressees were the Irish monks expelled from Pictland in AD 717, who had access to the letter of Abbot Ceolfrith, which included a problematic passage on the vernal equinox; this Bede tried to rectify in the Letter to Wicthed.
Warntjes, Immo, “An Irish eclipse prediction of AD 754: the earliest in the Latin West”, Peritia 24–25 (2013–2014): 108–115.
abstract:
This note announces the discovery of a tract on eclipse prediction in Paris, BnF, lat. 6400b, composed by an Irish scholar in AD 754. It is the earliest such text in the early middle ages and it is here placed in its scientific context.
Bisagni, Jacopo, “A new citation from a work of Columbanus in BnF lat. 6400b”, Peritia 24–25 (2013–2014): 116–122.
abstract:
The author argues that a section of the newly-discovered eighth-century Irish computistica in Paris, BnF, lat. 6400b may contain a citation from a (lost?) work of Columbanus.
Warntjes, Immo, “Seventh-century Ireland: the cradle of medieval science?”, in: Mary Kelly, and Charles Doherty (eds), Music and the stars: mathematics in medieval Ireland, Dublin: Four Courts Press, 2013. 44–72.
Darby, Peter, Bede and the end of time, Studies in Early Medieval Britain and Ireland, Farnham, Surrey, Burlington, VT: Ashgate, 2012. xv + 261 pp.
Warntjes, Immo, “Irische Komputistik zwischen Isidor von Sevilla und Beda Venerabilis: Ursprung, karolingische Rezeption und generelle Forschungsperspektiven”, Viator 42 (2011): 1–32.
abstract:
Computistical studies of the past centuries have primarily focused on the works of well-known individuals, while anonymous texts have been widely left unconsidered, leading to an immense overrating of the scientific achievements of the scholars known by name. Only within the past few years have the intellectual milieus that produced and influenced the known authors received some attention. This article defines on a textual basis Irish and Anglo-Saxon scientific milieus between Isidore of Seville and the Venerable Bede by providing a survey of all known computistical works of this period. On this basis, the Irish scientific contribution to the Carolingian educational and intellectual renaissance is assessed before the more general desiderata in the modern study of early medieval computistica are outlined at the end of this paper.
Cuppo, Luciana, “Felix of Squillace and the Dionysiac computus I: Bobbio and northern Italy (MS Ambrosiana H 150 inf.)”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), The Easter controversy of Late Antiquity and the early Middle Ages: its manuscripts, texts, and tables. Proceedings of the 2nd International Conference on the Science of Computus in Ireland and Europe, Galway, 18–20 July, 2008, 10, Turnhout: Brepols, 2011. 110–136.
abstract:
Thanks to a previously neglected fragment in the Bobbio Computus (MS Ambrosiana H 150 inf., 107v-109r) the original text of the computistical tract of Felix chillitanus can now be restored. On grounds of internal evidence and textual transmission its author can be identified as Felix of Squillace, a scholar of computus in the Alexandrian tradition propagated in the West by Dionysius Exiguus, then by Cassiodorus at Vivarium, and last by Felix in AD 616.

The fragment of Felix in the Bobbio Computus shows a recension independent from that known from the manuscripts Digby 63, 67r–v and 70v–71r, and Ambrosiana H 150 inf., 50v. It is inserted in the Etymologiae of Isidore (VI 17), but neither the arrangement of Isidore’s work nor the cycles in Etymologiae VI 17 resemble the standard edition. They may reflect the early organization of the work in fifteen books as arranged by Braulio, rather than the later division in twenty books attributed to Theodulf of Orléans.

The 95-year cycle also shows independent features. Though inserted in the Etymologiae and thus presumably Isidorian, it is quite unlike other known cycles from AD 627 to 721 (Ambrosiana L 99 sup., Digby 63). But there are also discrepancies between the contemporary cycles from 798 to 892 (Ambrosiana H 150 inf., 93v–98r) and those in the Felix/Isidore section of the same codex. Without further study we cannot determine when the texts of Isidore and Felix became known at Bobbio, but the evidence, such as it is, suggests that the Bobbio computist was not merely copying, but elaborating this material, and this fact may be indicative of a school of computistics at Bobbio in the seventh and eighth century.
Nic Dhonnchadha, Aoibheann, “[Various catalogue descriptions]”, Anne-Marie OʼBrien, and Pádraig Ó Macháin, Irish Script on Screen (ISOS) – Meamrám Páipéar Ríomhaire, Online: School of Celtic Studies, Dublin Institute for Advanced Studies, 2010–. URL: <https://www.isos.dias.ie>
Mc Carthy, Daniel P., “Bede’s primary source for the Vulgate chronology in his chronicles in De temporibus and De temporum ratione”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Computus and its cultural context in the Latin West, AD 300–1200: Proceedings of the 1st International Conference on the Science of Computus in Ireland and Europe, 5, Turnhout: Brepols, 2010. 159–189.
abstract:
Mommsen’s 1898 assumption that Bede had compiled the Vulgate chronology of his De temporibus and De temporum ratione has been simply reiterated by scholars ever since. But critical collation of Bede’s chronicles with the Irish Annals leads to the conclusion that their common features, including their Vulgate chronology, derive from a common source that originated in a chronicle compiled by Rufinus of Aquileia († 410). By the year 538, Rufinus’ chronicle was being continued in Ireland, and this continuation was transferred to Iona before the end of the sixth century. Around 687, Adomnán, then abbot of Iona, presented to Aldfrith, king of Northumbria, a copy of the world history in the Iona annals extending as far as the reign of the emperor Justinian, who ruled 685–695, and also a copy of his own De locis sanctis. By 703, these works had reached Bede and he compiled epitomes of them both. Subsequently, in 725, he again edited this copy of the Iona annals to compile his world-chronicle in De temporum ratione. Thus it was Adomnán’s copy of the Iona annals that served as Bede’s primary source for the Vulgate chronology of his De temporibus and De temporum ratione.
Warntjes, Immo, The Munich computus: text and translation. Irish computistics between Isidore of Seville and the Venerable Bede and its reception in Carolingian times, Stuttgart, 2010.
Howlett, David, “Computus in Hiberno-Latin literature”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Computus and its cultural context in the Latin West, AD 300–1200: Proceedings of the 1st International Conference on the Science of Computus in Ireland and Europe, 5, Turnhout: Brepols, 2010. 259–323.
abstract:
The essay begins with an Introduction to the history of the Latin language, computus, and related disciplines in Antiquity before knowledge of the subjects among the Irish; it proceeds with Part I, three Hiberno-Latin computistic texts, a note about the introduction of computus among the Irish, analysis of the beginning of Cummian’s Letter of 633 to Ségéne and Béccán, and an edition, translation, and analysis of the preliminaries and dating clause of the Oxford computus of 658; it proceeds with Part II, a survey of Computistic Phenomena in Hiberno-Latin Literature under twenty-three headings, considering texts from the fifth century to the twelfth; it ends with a Conclusion.
Graff, Eric, “The recension of two Sirmond texts: Disputatio Morini and De divisionibus temporum”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Computus and its cultural context in the Latin West, AD 300–1200: Proceedings of the 1st International Conference on the Science of Computus in Ireland and Europe, 5, Turnhout: Brepols, 2010. 112–142.
abstract:
This paper examines the tradition of the Sirmond computus, comparing Jones’ diagrammatic representations with new information from manuscript collations of Disputatio Morini and De diuisionibus temporum. These works represent two major components of the Sirmond compilation: the paschal letters collection and the texts used for teaching computus in the schools. By tracing their individual recensions, this paper aims to refine our understanding of the origin of these works and their places in the history of early medieval computistics.
Springsfeld, Kerstin, “Eine Beschreibung der Handschrift St. Gallen, Stiftsbibliothek, 225”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Computus and its cultural context in the Latin West, AD 300–1200: Proceedings of the 1st International Conference on the Science of Computus in Ireland and Europe, 5, Turnhout: Brepols, 2010. 204–237.
abstract:
MS St. Gallen, Stiftsbibliothek, 225 was probably compiled in 773. It contains 21 hitherto unexplored pages dealing with natural science and computistics: three tables (Easter table, Easter Sundays, lunar age), two schematic chapters (horologium and Julian calendar with multiplication-tables), eight computistical argumenta (dealing with the bissextile day, the annus mundi, the annus domini, the indiction, the concurrentes, common and embolismic lunar years, the annus passionis, the seasons), and two inserted chapters on ecclesiastical feastdays and Greek names. This material shows parallels with the Cologne textbook on time-reckoning of 805, as well as the encyclopaedia on time-reckoning from Aachen of 809; yet, this manuscript does not contain a cohesive work, but only disconnected computistical bits. It is evidently influenced by Irish computistical thought, but it also transmits Roman traditions through its lunar calculations, which were later promoted by Alcuin in the Carolingian kingdom. A pseudo-calculation of Irish-Frankish origin is mentioned in the context of the bissextile day. Likewise, a table listing all possible Easter Sundays depending on the weekday of the Easter full moon also derives from Irish-Frankish Easter calculations. This calculation, using certain regulars for March and April, is explained in the Calculatio Albini of 776, which is an adaptation of Irish material, presumably by Alcuin.
Ó Cróinín, Dáibhí, “The continuity of the Irish computistical tradition”, in: Immo Warntjes, and Dáibhí Ó Cróinín (eds), Computus and its cultural context in the Latin West, AD 300–1200: Proceedings of the 1st International Conference on the Science of Computus in Ireland and Europe, 5, Turnhout: Brepols, 2010. 324–347.
abstract:
It is well known that the study of computus in Ireland in the sixth and seventh centuries was at a level not equaled anywhere else in Europe, with the possible exception of Visigothic Spain. Not so well known, however, is the fact that computistics continued to thrive in Ireland, not only into the eighth and ninth centuries, but well beyond that. In fact, the eleventh and twelfth centuries saw a high-point of scholarly activity, in the related fields of chronology and chronography, both in Latin and in the vernacular. The best known Irish scholar of the period, Marianus Scottus of Fulda and Mainz, established a pattern for computistical and chronographical studies for centuries to come. This paper presents some of the evidence for that Blütezeit.
MIRABILE, Online: Studio del Medioevo Latino, 2009–present. URL: <http://www.mirabileweb.it>
abstract:
MIRABILE è un knowledge management system per lo studio e la ricerca sulla cultura medievale promosso dalla Società Internazionale per lo Studio del Medioevo Latino e dalla Fondazione Ezio Franceschini ONLUS di Firenze.
Bisagni, Jacopo, and Immo Warntjes, “The early Old Irish material in the newly discovered Computus Einsidlensis (c. AD 700)”, Ériu 58 (2008): 77–105.
The calendar and the cloister: Oxford, St John's College MS 17, Online: McGill University Library, Digital Collections Program, 2007–present. URL: <http://digital.library.mcgill.ca/ms-17/>
abstract:
The calendar and the cloister is a scholarly resource devoted to a single medieval manuscript: Oxford, St John's College 17. This splendid volume was created in the first decade of the 12th century at Thorney Abbey, a Benedictine monastery in Cambridgeshire. Its importance for the cultural and intellectual history of Anglo-Saxon and Anglo-Norman England has been recognized since the 16th century by historians, philologists, and scholars working in the fields of medieval science, monastic culture, and the history of the book.
Bisagni, Jacopo, and Immo Warntjes, “Latin and Old Irish in the Munich computus: a reassessment and further evidence”, Ériu 57 (2007): 1–33.
abstract:
This article analyses the relatively rare phenomenon of code-switching and code-mixing from Latin to Old Irish in the Munich Computus. All (including previously unnoticed) instances of Old Irish in this Latin text are discussed, both from the linguistic point of view and as regards the reasons for their application. The author of the Munich Computus, writing in AD 719 and consequently being one of the earliest compilers of a comprehensive computistical textbook, faced the difficult task of transferring classroom teaching into writing without a model for this task at hand. In this context, it is argued that the shift to an informal register (Old Irish) was employed to serve specific didactical purposes, to facilitate the understanding of complicated technical material. Additionally, this analysis sheds more light on the function and nature of the Munich Computus itself.
Gautier, Marc-Édouard, “Aux origines du dessin généalogique en France: l’exemple de l’abbaye Saint-Aubin d’Angers (XIe–XIIe siècle)”, Archives d’Anjou: mélanges d’histoire et d’archéologie angevines 11 (2007): 5–33.
Warntjes, Immo, “The Munich Computus and the 84 (14)-year Easter reckoning”, Proceedings of the Royal Irish Academy 107 C (2007): 31–85.
abstract:
The construction, and especially the assignment of the Easter dates, of the Easter reckoning used in the British Isles from the fifth to the eighth century, here called the 84 (14), has been a matter of scholarly debate for the past 400 years. Since the discovery of the Munich Computus in AD 1878, the text that became the primary source for this Easter reckoning, the debate has centred almost exclusively on it. This changed with the discovery of an Easter table of this reckoning in AD 1985, which provided reliable Easter dates as well as a most valuable insight into the construction of the table itself. However, these primary sources have never been compared thoroughly. Such a comparison is provided in the present article, which leads to an analysis of its implications for the 84 (14) in general, and for the Munich Computus in particular.
Eastwood, Bruce S., Ordering the heavens: Roman astronomy and cosmology in the Carolingian Renaissance, History of Science and Medicine Library, 4, Leiden, Boston: Brill, 2007.
Bracken, Damian, “Virgil the Grammarian and Bede: a preliminary study”, Anglo-Saxon England 35 (2006): 7–21.
abstract:
The chapters in Bede's De temporum ratione begin with an etymology for the name of the subject to be examined. Sources and analogues for some have not hitherto been identified. This article shows that some of these etymologies of words for the divisions of time come ultimately, though perhaps not directly, from bk XI of Virgil the Grammarian's Epitomae. These accounts of the origins of calendrical and cosmological terms wound their way through early western computistical works and eventually into Bede's De temporum ratione. The article identifies examples of Virgil's influence on anonymous early medieval biblical commentaries and discusses their significance as pointers towards their place of composition.
Baker, Peter S., “More diagrams by Byrhtferth of Ramsey”, in: Katherine OʼBrien OʼKeeffe, and Andy Orchard (eds), Latin learning and English lore: studies in Anglo-Saxon literature for Michael Lapidge, 2 vols, vol. 2, Toronto: University of Toronto Press, 2005. 53–73.
Lambert, Pierre-Yves, “Les gloses en vieux-breton aux écrits scientifiques de Bède, dans le manuscrit Angers 477”, in: Stéphane Lebecq, Michel Perrin, and Olivier Szerwiniack (eds), Bède le Vénérable: entre tradition et posterité, 34, Villeneuve d'Ascq, 2005. 309–319.
Hleno.revues.org: <link>
Warntjes, Immo, “A newly-discovered Irish computus: computus Einsidlensis”, Peritia 19 (2005): 61–64.
Graff, Eric, “The thirteenth figure in the Munich computus zodiac”, Journal for the History of Astronomy 36 (2005): 321–334.
Wallis, Faith, “‘Number mystique’ in early medieval computus texts”, in: Teun Koetsier, and Luc Bergmans (eds), Mathematics and the divine: a historical study, Amsterdam: Elsevier Science, 2005. 179–199.
Ó Cróinín, Dáibhí, “Bede’s Irish computus”, in: Dáibhí Ó Cróinín, Early Irish history and chronology, Dublin: Four Courts Press, 2003. 201–212.
Lambert, Pierre-Yves, “The Old Welsh glosses on weights and measures”, in: Paul Russell (ed.), Yr hen iaith: studies in early Welsh, 7, Aberystwyth: Celtic Studies Publications, 2003. 103–134.
Springsfeld, Kerstin, Alkuins Einfluss auf die Komputistik zur Zeit Karls des Grossen, Sudhoffs Archiv Beihefte, 48, Stuttgart: Steiner, 2002.
Charles-Edwards, T. M., Early Christian Ireland, Cambridge: Cambridge University Press, 2000.
Wallis, Faith, Bede: The reckoning of time, Liverpool: Liverpool University Press, 1999.
Ó Cróinín, Dáibhí, “The computistical works of Columbanus”, in: Michael Lapidge (ed.), Columbanus: studies on the Latin writings, 17, Woodbridge: Boydell Press, 1997. 264–270.
Baker, Peter S., and Michael Lapidge, Byrhtferth’s Enchiridion, Early English Text Society, 15, Oxford: Oxford University Press, 1995.
Sims-Williams, Patrick, “Byrhtferth’s ogam signature”, in: Tegwyn Jones, and E. B. Fryde (eds), Ysgrifau a cherddi cyflwynedig i Daniel Huws: Essays and poems presented to Daniel Huws, Aberystwyth: National Library of Wales, 1994. 283–291.
Schneiders, Marc, “The Irish calendar in the Karlsruhe Bede (Karlsruhe, Badische Landesbibliothek, Cod. Aug. CLXVII, ff. 16v-17v)”, Archiv für Liturgiewissenschaft 31 (1989): 33–78.
Schneiders, Marc, “Zur Datierung und Herkunft des Karlsruher Beda (Aug. CLXVII)”, Scriptorium 43:2 (1989): 247–252, pl. 19.
Persée: <link>
Muir, Bernard James [ed.], A pre-Conquest English prayer-book (BL MSS Cotton Galba A.xiv and Nero A.ii (ff. 3-13)), Henry Bradshaw Society, 103, Woodbridge: Boydell Press, 1988.
Walsh, Maura, and Dáibhí Ó Cróinín, Cummian’s letter De controversia Paschali: together with a related Irish computistical tract De ratione conputandi, Studies and Texts, 86, Toronto: Pontifical Institute of Mediaeval Studies, 1988.
CELT – De controversia Paschali, text (pp. 56–96): <link> CELT – De controversia Paschali, translation (pp. 57–95): <link>
Lambert, Pierre-Yves, “Les commentaires celtiques à Bède le Vénérable [part 2]”, Études Celtiques 21 (1984): 185–206.
Journal volume:  Persée – Études Celtiques, vol. 21, 1984: <link>
Heinzer, Felix, “Zur Datierung des Karlsruher Beda (Aug. CLXVII)”, Scriptorium 37:2 (1983): 239–241, pl. 23.
Persée: <link>
Ó Cróinín, Dáibhí, “The Irish provenance of Bede’s computus”, Peritia 2 (1983): 229–247.