Smithsonian Institution. Office of the Secretary & Ridgway, R. (1920). Diagnoses of some new genera of birds. [publisher not identified].
Chicago Style (17th ed.) CitationSmithsonian Institution. Office of the Secretary and Robert Ridgway. Diagnoses of Some New Genera of Birds. Washington, D.C.: [publisher not identified], 1920.
MLA (9th ed.) CitationSmithsonian Institution. Office of the Secretary and Robert Ridgway. Diagnoses of Some New Genera of Birds. [publisher not identified], 1920.
Warning: These citations may not always be 100% accurate.