APA (7th ed.) Citation

Halperin, S. W. (1961). Some 20th century historians. Chic. U.P..

Chicago Style (17th ed.) Citation

Halperin, S. William. Some 20th Century Historians. Chic.: Chic. U.P., 1961.

MLA (8th ed.) Citation

Halperin, S. William. Some 20th Century Historians. Chic. U.P., 1961.

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