MLA

Saarinen, Eero, 1910-1961. Exteriors. Box 420, folder 1181. 1964, undated. https://collections.library.yale.edu/catalog/10013602.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 420, folder 1181"])(1964, undated)[Exteriors]. https://collections.library.yale.edu/catalog/10013602.