MLA

Valéry, Paul, 1871-1945. Paul Valéry collection, 1896-1939. Box 1. https://collections.library.yale.edu/catalog/16538030.

APA, 6th edition

Valéry, Paul, 1871-1945. (["Box 1"])[Paul Valéry collection, 1896-1939]. https://collections.library.yale.edu/catalog/16538030.