MLA

McKay, Claude, 1890-1948. "North and South," typescript carbon. Box 12, folder 385. n.d.. https://collections.library.yale.edu/catalog/32269401.

APA, 6th edition

McKay, Claude, 1890-1948. (["Box 12, folder 385"])(n.d.)["North and South," typescript carbon]. https://collections.library.yale.edu/catalog/32269401.