MLA

Du Bois, W. E. B. (William Edward Burghardt), 1868-1963. "White Masters of the World", two versions: typescript, corrected and typescript carbon. Box 4, folder 89. n.d.. https://collections.library.yale.edu/catalog/2040394.

APA, 6th edition

Du Bois, W. E. B. (William Edward Burghardt), 1868-1963. (["Box 4, folder 89"])(n.d.)["White Masters of the World", two versions: typescript, corrected and typescript carbon]. https://collections.library.yale.edu/catalog/2040394.