MLA

McKay, Claude, 1890-1948. "Group Life and Literature," typescript carbon, corrected. Box 9, folder 287. n.d.. https://collections.library.yale.edu/catalog/16742362.

APA, 6th edition

McKay, Claude, 1890-1948. (["Box 9, folder 287"])(n.d.)["Group Life and Literature," typescript carbon, corrected]. https://collections.library.yale.edu/catalog/16742362.