MLA

Saarinen, Eero, 1910-1961. Various. Box 12, folder 190. undated. https://collections.library.yale.edu/catalog/10020362.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 12, folder 190"])(undated)[Various]. https://collections.library.yale.edu/catalog/10020362.