Waksman, S. A. (1938). Humus: Origin, chemical composition, and importance in nature (2d. rev. ed.). The Williams & Wilkins company.
Chicago Style (17th ed.) CitationWaksman, Selman A. Humus: Origin, Chemical Composition, and Importance in Nature. 2d. rev. ed. Baltimore: The Williams & Wilkins company, 1938.
MLA (9th ed.) CitationWaksman, Selman A. Humus: Origin, Chemical Composition, and Importance in Nature. 2d. rev. ed. The Williams & Wilkins company, 1938.
Warning: These citations may not always be 100% accurate.