MLA

Saarinen, Eero, 1910-1961. Observation platform. Box 455, folder 1259. 1936-1989. https://collections.library.yale.edu/catalog/10017277.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 455, folder 1259"])(1936-1989)[Observation platform]. https://collections.library.yale.edu/catalog/10017277.