MLA

Lewis, Sinclair, 1885-1951. "Legal Residence of Sinclair Lewis in Massachusetts--State Will Get Sizable Sum in Inheritance Taxes". Box 69, folder 954. 1951 January 20. https://collections.library.yale.edu/catalog/17116563.

APA, 6th edition

Lewis, Sinclair, 1885-1951. (["Box 69, folder 954"])(1951 January 20)["Legal Residence of Sinclair Lewis in Massachusetts--State Will Get Sizable Sum in Inheritance Taxes"]. https://collections.library.yale.edu/catalog/17116563.