For the Catholic Easter and the Roman Tonsure (Paperback) (ISBN-13: 9798868900235)

This is a text that is looking to reconcile the Celtic Church to that of the Roman tradition. This was particularly salient with the two titular issues, as the early Celtic church observed both a different date for East (separate from the Greek) and maintained a different style of monastic tonsure. These issue would come to a head at the Synod of Whitby in 664 AD, when formal reconciliation was suppose to have taken place.