APA (7th ed.) Citation

Smithsonian Institution. (1940). Two new races of passerine birds from Thailand. [s.n.].

Chicago Style (17th ed.) Citation

Smithsonian Institution. Two New Races of Passerine Birds from Thailand. [Washington]: [s.n.], 1940.

MLA (9th ed.) Citation

Smithsonian Institution. Two New Races of Passerine Birds from Thailand. [s.n.], 1940.

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