"Paid and Exchange Ads"
MLA
Thayer, Scofield, 1889-1982. "Paid and Exchange Ads". Box 14, folder 339. 1920-22. https://collections.library.yale.edu/catalog/2046725.
APA, 6th edition
Thayer, Scofield, 1889-1982. (["Box 14, folder 339"])(1920-22)["Paid and Exchange Ads"]. https://collections.library.yale.edu/catalog/2046725.