APA (7th ed.) Citation

Knowles, D. (1957). Cardinal Gasquet as an historian. University of London [etc.].

Chicago Style (17th ed.) Citation

Knowles, David. Cardinal Gasquet as an Historian. London: University of London [etc.], 1957.

MLA (9th ed.) Citation

Knowles, David. Cardinal Gasquet as an Historian. University of London [etc.], 1957.