MLA

Jordan, Viola Baxter, 1887-1973. Schaffner, Perdita. Box 3, folder 94. 1920 Jan 1. https://collections.library.yale.edu/catalog/17207717.

APA, 6th edition

Jordan, Viola Baxter, 1887-1973. (["Box 3, folder 94"])(1920 Jan 1)[Schaffner, Perdita]. https://collections.library.yale.edu/catalog/17207717.