MLA

Hansen, Bert, 1944-. "Prescribed By His Doctor. Calisthenic exercise to decrease Mr. Dustwad's growing adiposity.". Box 12, folder 1. 1910 September 21. https://collections.library.yale.edu/catalog/32331912.

APA, 6th edition

Hansen, Bert, 1944-. (["Box 12, folder 1"])(1910 September 21)["Prescribed By His Doctor. Calisthenic exercise to decrease Mr. Dustwad's growing adiposity."]. https://collections.library.yale.edu/catalog/32331912.