MLA

Wilfred, Thomas, 1889-1968. Keyboard. Box 10, folder 145. Undated. https://collections.library.yale.edu/catalog/10019437.

APA, 6th edition

Wilfred, Thomas, 1889-1968. (["Box 10, folder 145"])(Undated)[Keyboard]. https://collections.library.yale.edu/catalog/10019437.