MLA

McKay, Claude, 1890-1948. "Negro Dancers," typescript carbon. Box 12, folder 378. n.d.. https://collections.library.yale.edu/catalog/32268871.

APA, 6th edition

McKay, Claude, 1890-1948. (["Box 12, folder 378"])(n.d.)["Negro Dancers," typescript carbon]. https://collections.library.yale.edu/catalog/32268871.