APA (7th ed.) Citation

Spangler, P. J., & Perkins, P. D. (1989). A revision of the neotropical aquatic beetle genus Stenhelmoides (Coleoptera: Elmidae). Smithsonian Institution Press.

Chicago Style (17th ed.) Citation

Spangler, Paul J., and Philip D. Perkins. A Revision of the Neotropical Aquatic Beetle Genus Stenhelmoides (Coleoptera: Elmidae). Washington, D.C.: Smithsonian Institution Press, 1989.

MLA (9th ed.) Citation

Spangler, Paul J., and Philip D. Perkins. A Revision of the Neotropical Aquatic Beetle Genus Stenhelmoides (Coleoptera: Elmidae). Smithsonian Institution Press, 1989.