APA (7th ed.) Citation

Calkins, G. N. (1933). The biology of the protozoa (2d ed., thoroughly rev.). Lea & Febiger.

Chicago Style (17th ed.) Citation

Calkins, Gary N. The Biology of the Protozoa. 2d ed., thoroughly rev. Philadelphia: Lea & Febiger, 1933.

MLA (9th ed.) Citation

Calkins, Gary N. The Biology of the Protozoa. 2d ed., thoroughly rev. Lea & Febiger, 1933.