MLA

O'Neill, Eugene, Jr., 1910-1950. Correspondence. Box 1, folder 38. 1950. https://collections.library.yale.edu/catalog/10257489.

APA, 6th edition

O'Neill, Eugene, Jr., 1910-1950. (["Box 1, folder 38"])(1950)[Correspondence]. https://collections.library.yale.edu/catalog/10257489.