MLA

Saarinen, Eero, 1910-1961. Model. Box 168, folder 501. 1955, undated. https://collections.library.yale.edu/catalog/10017570.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 168, folder 501"])(1955, undated)[Model]. https://collections.library.yale.edu/catalog/10017570.