APA (7th ed.) Citation

United States. Office of Education & Kirkwood, J. E. (1918). Conifers of northern Rockies. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Office of Education and J. E. Kirkwood. Conifers of Northern Rockies. Washington: U.S. GPO, 1918.

MLA (9th ed.) Citation

United States. Office of Education and J. E. Kirkwood. Conifers of Northern Rockies. U.S. GPO, 1918.