MLA

Saarinen, Eero, 1910-1961. Final models. Box 566, folder 1541. undated. https://collections.library.yale.edu/catalog/10017355.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 566, folder 1541"])(undated)[Final models]. https://collections.library.yale.edu/catalog/10017355.