MLA

Roskolenko, Harry, 1907-1980. Villa, Jose Garcia. Box 1, folder 100. 1949 Apr 4. https://collections.library.yale.edu/catalog/17204974.

APA, 6th edition

Roskolenko, Harry, 1907-1980. (["Box 1, folder 100"])(1949 Apr 4)[Villa, Jose Garcia]. https://collections.library.yale.edu/catalog/17204974.