MLA

Schwartz, Delmore, 1913-1966. Notes filed among the notebooks. Box 20, folder 815-817. 1951-1965. https://collections.library.yale.edu/catalog/2064470.

APA, 6th edition

Schwartz, Delmore, 1913-1966. (["Box 20, folder 815-817"])(1951-1965)[Notes filed among the notebooks]. https://collections.library.yale.edu/catalog/2064470.