MLA

Birom Farmer, Nigeria, Ca. 1920-1940. 1920. https://collections.library.yale.edu/catalog/11447142.

APA, 6th edition

Birom farmer, Nigeria, ca. 1920-1940. (1920). [Photographic postcards (AAT), photographs (AAT), portraits (AAT)]. https://collections.library.yale.edu/catalog/11447142.