"Mabel Dodge Luhan was round and square" button
MLA
Luhan, Mabel Dodge, 1879-1962. "Mabel Dodge Luhan was round and square" button. Box 5, folder 88a. n.d.. https://collections.library.yale.edu/catalog/2003135.
APA, 6th edition
Luhan, Mabel Dodge, 1879-1962. (["Box 5, folder 88a"])(n.d.)["Mabel Dodge Luhan was round and square" button]. https://collections.library.yale.edu/catalog/2003135.