MLA

Bartlett, Henrietta C. (Henrietta Collins), 1873-1963. McKerrow, Ronald Brunlees. Box 3, folder 151. 1912-34. https://collections.library.yale.edu/catalog/17341676.

APA, 6th edition

Bartlett, Henrietta C. (Henrietta Collins), 1873-1963. (["Box 3, folder 151"])(1912-34)[McKerrow, Ronald Brunlees]. https://collections.library.yale.edu/catalog/17341676.