APA (7th ed.) Citation

Blake, S. F. (1922). Key to genus Diplostephium, with descriptions of new species. U.S. Government Printing Office.

Chicago Style (17th ed.) Citation

Blake, S. F. Key to Genus Diplostephium, with Descriptions of New Species. [Place of publication not identified]: U.S. Government Printing Office, 1922.

MLA (9th ed.) Citation

Blake, S. F. Key to Genus Diplostephium, with Descriptions of New Species. U.S. Government Printing Office, 1922.