APA (7th ed.) Citation

Cox, G. W. (1891). The crusades (9th ed.). Longmans, Green, and co..

Chicago Style (17th ed.) Citation

Cox, George W. The Crusades. 9th ed. London ; New York: Longmans, Green, and co., 1891.

MLA (8th ed.) Citation

Cox, George W. The Crusades. 9th ed. Longmans, Green, and co., 1891.