APA (7th ed.) Citation

Longyear, B. O. (1927). Trees and shrubs of the Rocky mountain region: With keys and descriptions for their identification. G.P. Putnam's sons.

Chicago Style (17th ed.) Citation

Longyear, Burton Orange. Trees and Shrubs of the Rocky Mountain Region: With Keys and Descriptions for Their Identification. New York London: G.P. Putnam's sons, 1927.

MLA (9th ed.) Citation

Longyear, Burton Orange. Trees and Shrubs of the Rocky Mountain Region: With Keys and Descriptions for Their Identification. G.P. Putnam's sons, 1927.