MLA

Longstreet, Stephen, 1907-2002. Work song. Box 4, folder 21. 1927. https://collections.library.yale.edu/catalog/32458569.

APA, 6th edition

Longstreet, Stephen, 1907-2002. (["Box 4, folder 21"])(1927)[Work song]. https://collections.library.yale.edu/catalog/32458569.