APA (7th ed.) Citation

Sudworth, G. B. (1934). Poplars, principal tree willows and walnuts of the Rocky Mountain region. U.S. Dept. of Agriculture.

Chicago Style (17th ed.) Citation

Sudworth, George B. Poplars, Principal Tree Willows and Walnuts of the Rocky Mountain Region. Washington: U.S. Dept. of Agriculture, 1934.

MLA (9th ed.) Citation

Sudworth, George B. Poplars, Principal Tree Willows and Walnuts of the Rocky Mountain Region. U.S. Dept. of Agriculture, 1934.