APA (7th ed.) Citation

Knowlton, F. H. (1891). Directions for collecting recent and fossil plants. U.S. G.P.O..

Chicago Style (17th ed.) Citation

Knowlton, Frank Hall. Directions for Collecting Recent and Fossil Plants. Washington: U.S. G.P.O., 1891.

MLA (9th ed.) Citation

Knowlton, Frank Hall. Directions for Collecting Recent and Fossil Plants. U.S. G.P.O., 1891.