APA (7th ed.) Citation

Lewis, H., & Lewis, M. R. E. (1955). The genus Clarkia. [publisher not identified].

Chicago Style (17th ed.) Citation

Lewis, Harlan, and Margaret Ruth Ensign Lewis. The Genus Clarkia. Berkeley, University of California Press: [publisher not identified], 1955.

MLA (9th ed.) Citation

Lewis, Harlan, and Margaret Ruth Ensign Lewis. The Genus Clarkia. [publisher not identified], 1955.