MLA

Thomson, Virgil, 1896-1989. Barber, Samuel. Box 29/23, folder 26. 1951-1982. https://collections.library.yale.edu/catalog/32231741.

APA, 6th edition

Thomson, Virgil, 1896-1989. (["Box 29/23, folder 26"])(1951-1982)[Barber, Samuel]. https://collections.library.yale.edu/catalog/32231741.