MLA

Cassirer, Ernst, 1874-1945. Draft A, holograph, corrected. Box 42, folder 825. 1937. https://collections.library.yale.edu/catalog/17274632.

APA, 6th edition

Cassirer, Ernst, 1874-1945. (["Box 42, folder 825"])(1937)[Draft A, holograph, corrected]. https://collections.library.yale.edu/catalog/17274632.