MLA

Wolff, Kurt, 1887-1963. Tzara, Tristan. Box 7, folder 298. 1919-21. https://collections.library.yale.edu/catalog/2021371.

APA, 6th edition

Wolff, Kurt, 1887-1963. (["Box 7, folder 298"])(1919-21)[Tzara, Tristan]. https://collections.library.yale.edu/catalog/2021371.