MLA

Gellert, Lawrence, 1898-1979. Negro songs of protest. Box 2 | Folder 32. [193-]. https://collections.library.yale.edu/catalog/10589567.

APA, 6th edition

Gellert, Lawrence, 1898-1979. (["Box 2 | Folder 32"])([193-])[Negro songs of protest]. https://collections.library.yale.edu/catalog/10589567.