MLA

Hansen, Bert, 1944-. "The Retort Brutal. 'Here, in this gallery, are portraits of some of my ancestors.' 'Humph! They evidently looked upon Eugenics as a joke'!". Box 12, folder 12. 1913 March 26. https://collections.library.yale.edu/catalog/32331920.

APA, 6th edition

Hansen, Bert, 1944-. (["Box 12, folder 12"])(1913 March 26)["The Retort Brutal. 'Here, in this gallery, are portraits of some of my ancestors.' 'Humph! They evidently looked upon Eugenics as a joke'!"]. https://collections.library.yale.edu/catalog/32331920.