MLA

Spence, Joseph, 1699-1768. Garden Plans, Unidentified. Box 6, folder 213. n.d.. https://collections.library.yale.edu/catalog/16671738.

APA, 6th edition

Spence, Joseph, 1699-1768. (["Box 6, folder 213"])(n.d.)[Garden Plans, Unidentified]. https://collections.library.yale.edu/catalog/16671738.