APA (7th ed.) Citation

Penney, J. T., & Racek, A. A. (1968). Comprehensive revision of a worldwide collection of freshwater sponges (Porifera: Spongillidae). Smithsonian Inst. Press.

Chicago Style (17th ed.) Citation

Penney, James Theophilus, and A. A. Racek. Comprehensive Revision of a Worldwide Collection of Freshwater Sponges (Porifera: Spongillidae). Washington: Smithsonian Inst. Press, 1968.

MLA (9th ed.) Citation

Penney, James Theophilus, and A. A. Racek. Comprehensive Revision of a Worldwide Collection of Freshwater Sponges (Porifera: Spongillidae). Smithsonian Inst. Press, 1968.