APA (7th ed.) Citation

(1941). Cyclophorid operculate land mollusks of America. [s.n.].

Chicago Style (17th ed.) Citation

Cyclophorid Operculate Land Mollusks of America. [Washington]: [s.n.], 1941.

MLA (9th ed.) Citation

Cyclophorid Operculate Land Mollusks of America. [s.n.], 1941.