Dr Holt reported on his project to identify the "most important" books on the Crusades. He asked 34 leading medieval historians to provide their own preferential list. Their replies resulted in a list of some 150 titles. Analyzing this as to the number of times each title had been mentioned by the scolars, Dr Holt identified "the 15 most important Books on the Crusades". The titles are shown below, including the number of times each title was mentioned.