MLA

Wolff, Kurt, 1887-1963. Hülsenbeck, Richard. Box 5, folder 158. 1920. https://collections.library.yale.edu/catalog/2021312.

APA, 6th edition

Wolff, Kurt, 1887-1963. (["Box 5, folder 158"])(1920)[Hülsenbeck, Richard]. https://collections.library.yale.edu/catalog/2021312.