APA (7th ed.) Citation

Blake, S. F. (1921). Revisions of genera Acanthospermum, Flourensia, Oyedaea, and Tithonia. U.S. Government Printing Office.

Chicago Style (17th ed.) Citation

Blake, S. F. Revisions of Genera Acanthospermum, Flourensia, Oyedaea, and Tithonia. [Place of publication not identified]: U.S. Government Printing Office, 1921.

MLA (9th ed.) Citation

Blake, S. F. Revisions of Genera Acanthospermum, Flourensia, Oyedaea, and Tithonia. U.S. Government Printing Office, 1921.