MLA

Hansen, Bert, 1944-. "Our Midsummer New-Thought Treatment. Concentration on this picture for five minutes will be found to equal two Mint Juleps and a cold shower bath.". Box 11, folder 27. 1909 August 11. https://collections.library.yale.edu/catalog/32326838.

APA, 6th edition

Hansen, Bert, 1944-. (["Box 11, folder 27"])(1909 August 11)["Our Midsummer New-Thought Treatment. Concentration on this picture for five minutes will be found to equal two Mint Juleps and a cold shower bath."]. https://collections.library.yale.edu/catalog/32326838.