Unidentified
MLA
O'Neill, Eugene, 1888-1953. Unidentified. Box 4, folder 73. undated. https://collections.library.yale.edu/catalog/32306580.
APA, 6th edition
O'Neill, Eugene, 1888-1953. (["Box 4, folder 73"])(undated)[Unidentified]. https://collections.library.yale.edu/catalog/32306580.