APA (7th ed.) Citation

Waksman, S. A. (1938). Humus: Origin, chemical composition, and importance in nature (2a. ed.). Williams and Wilkins.

Chicago Style (17th ed.) Citation

Waksman, Selman A. Humus: Origin, Chemical Composition, and Importance in Nature. 2a. ed. Baltimore: Williams and Wilkins, 1938.

MLA (9th ed.) Citation

Waksman, Selman A. Humus: Origin, Chemical Composition, and Importance in Nature. 2a. ed. Williams and Wilkins, 1938.