APA (7th ed.) Citation

United States. Bureau of Biological Survey. (1939). Food of game ducks in United States and Canada. [s.n.].

Chicago Style (17th ed.) Citation

United States. Bureau of Biological Survey. Food of Game Ducks in United States and Canada. [Washington]: [s.n.], 1939.

MLA (9th ed.) Citation

United States. Bureau of Biological Survey. Food of Game Ducks in United States and Canada. [s.n.], 1939.

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