APA (7th ed.) Citation

Routh, C. R. N. (1960). Who's who in history. Blackwell.

Chicago Style (17th ed.) Citation

Routh, C. R. N. Who's Who in History. Oxford: Blackwell, 1960.

MLA (9th ed.) Citation

Routh, C. R. N. Who's Who in History. Blackwell, 1960.