* The Religious Orders in England (3 bind)
* Benediktinerne i England
* Den engelske religiøse tradisjonen
* The Life and Times of St. Gregory the Great
* Fra Pachomius til Ignatius:A Study in the Constitutional History of the Religious Orders
* The Monastic Order in England:A History of its Development from the Times of St. Dunstan to the Fourth Lateran Council
* Kristen monastisisme
* Utviklingen av middelalderske tanker
* Historikeren og karakteren
* Great Historical Enterprises:A Comparative Study
Artikler:
* "Monastismens plass i kirken"
* "De religiøse ordener i middelalderen"
* "Benediktineridealet"
* "Cistercienserne"
* "Fransiskanerne"
* "Dominikanerne"
* "Karmelittene"
* "Augustinerne"
* "Premonstratenserne"
* "The Gilbertines"
Andre skrifter:
* Redaktør, The Oxford Dictionary of the Christian Church
* Bidragsyter, The Cambridge Ancient History
* Bidragsyter, The Cambridge Medieval History
* Bidragsyter, The New Cambridge Modern History