MLA

Saarinen, Eero, 1910-1961. "News from TWA" press packets. Box 330, folder 932. undated. https://collections.library.yale.edu/catalog/10017508.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 330, folder 932"])(undated)["News from TWA" press packets]. https://collections.library.yale.edu/catalog/10017508.