 After his initial 1964 article on Cistercian Abbots in Medieval Gwent, further publications included the work Llantarnam Abbey (1967); White Monks in Gwent and the Border; The Welsh Cistercians I & II; The Cistercians in the Middle Ages and Catalogue of Welsh Ecclesiastical Seals as known down to AD 1600; Atlas of Cistercian Lands in Wales; Catalogue of Welsh Ecclesiastical Seals in the National Museum of Wales I. Gwent Seals