APA (7th ed.) Citation

WATT, W. M. (1968). What is Islam. Longmans.

Chicago Style (17th ed.) Citation

WATT, W. Montgomery. What Is Islam. London: Longmans, 1968.

MLA (9th ed.) Citation

WATT, W. Montgomery. What Is Islam. Longmans, 1968.

Warning: These citations may not always be 100% accurate.