APA (7th ed.) Citation

Critchfield, W. B., & Little, E. L. (1966). Geographic distribution of the pines of the world.

Chicago Style (17th ed.) Citation

Critchfield, William Burke, and Elbert Luther Little. Geographic Distribution of the Pines of the World. Washington, DC, 1966.

MLA (9th ed.) Citation

Critchfield, William Burke, and Elbert Luther Little. Geographic Distribution of the Pines of the World. 1966.