MLA

Wilder, Thornton, 1897-1975. Correspondence. Box 6, folder 130. 1950-53. https://collections.library.yale.edu/catalog/17418518.

APA, 6th edition

Wilder, Thornton, 1897-1975. (["Box 6, folder 130"])(1950-53)[Correspondence]. https://collections.library.yale.edu/catalog/17418518.