MLA

Saarinen, Eero, 1910-1961. Desk calendars, monthly. Box 696, folder 195. 1951 July-1961 September. https://collections.library.yale.edu/catalog/10017976.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 696, folder 195"])(1951 July-1961 September)[Desk calendars, monthly]. https://collections.library.yale.edu/catalog/10017976.