MLA

Saarinen, Eero, 1910-1961. Models. Box 265, folder 843. undated. https://collections.library.yale.edu/catalog/10017179.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 265, folder 843"])(undated)[Models]. https://collections.library.yale.edu/catalog/10017179.