APA (7th ed.) Citation

Smithsonian Institution. (1922). Studies of tropical American ferns, No. 7. GPO.

Chicago Style (17th ed.) Citation

Smithsonian Institution. Studies of Tropical American Ferns, No. 7. [Washington]: GPO, 1922.

MLA (9th ed.) Citation

Smithsonian Institution. Studies of Tropical American Ferns, No. 7. GPO, 1922.

Warning: These citations may not always be 100% accurate.