APA (7th ed.) Citation

(1940). Variations and relationships in snakes of genus Pituophis. [s.n.].

Chicago Style (17th ed.) Citation

Variations and Relationships in Snakes of Genus Pituophis. [Washington]: [s.n.], 1940.

MLA (9th ed.) Citation

Variations and Relationships in Snakes of Genus Pituophis. [s.n.], 1940.

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