MLA

Saarinen, Eero, 1910-1961. Models. Box 420, folder 1187. undated. https://collections.library.yale.edu/catalog/10017675.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 420, folder 1187"])(undated)[Models]. https://collections.library.yale.edu/catalog/10017675.