APA (7th ed.) Citation

Gruber, H. (1964). Paul Levi and the Comintern.

Chicago Style (17th ed.) Citation

Gruber, Helmut. Paul Levi and the Comintern. 1964.

MLA (9th ed.) Citation

Gruber, Helmut. Paul Levi and the Comintern. 1964.

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