MLA

Argus Book Shop (Chicago, Ill.). McCullers, Carson. Box 7, folder 277. 1940-1942. https://collections.library.yale.edu/catalog/17158118.

APA, 6th edition

Argus Book Shop (Chicago, Ill.). (["Box 7, folder 277"])(1940-1942)[McCullers, Carson]. https://collections.library.yale.edu/catalog/17158118.