MLA

Williams, William Carlos, 1883-1963. Various poems translated from Spanish into English. Box 65, folder 1369. undated. https://collections.library.yale.edu/catalog/17049609.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 65, folder 1369"])(undated)[Various poems translated from Spanish into English]. https://collections.library.yale.edu/catalog/17049609.