Isidore of Seville
See also references for related subjects.
Warntjes, Immo, “Irische Komputistik zwischen Isidor von Sevilla und Beda Venerabilis: Ursprung, karolingische Rezeption und generelle Forschungsperspektiven”, Viator 42 (2011): 1–32.  
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.
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.
Hofman, Rijcklof, “Isidore in the St. Gall glosses”, in: Ní Chatháin, Próinséas, and Michael Richter (eds.), Irland und Europa im früheren Mittelalter: Bildung und Literatur / Ireland and Europe in the early Middle Ages: learning and literature, Stuttgart: Klett-Cotta, 1996. 173–186.
Fontaine, Jacques, Isidore de Séville: Traité de la nature; suivi de l’Épître en vers du roi Sisebut à Isidore, Bibliothèque de l’École des Hautes Études Hispaniques 28, Bordeaux: Féret, 1960.