APA (7th ed.) Citation

Spooner, D. M. (1990). Systematics of Simsia (Compositae-Heliantheae). American Society of Plant Taxonomists.

Chicago Style (17th ed.) Citation

Spooner, David M. Systematics of Simsia (Compositae-Heliantheae). Ann Arbor, Mich.: American Society of Plant Taxonomists, 1990.

MLA (9th ed.) Citation

Spooner, David M. Systematics of Simsia (Compositae-Heliantheae). American Society of Plant Taxonomists, 1990.