Cite

Keller, E.[lizabeth Leavitt?] to "Mr. Powers"

MLA

Whitman, Walt, 1819-1892. Keller, E.[lizabeth Leavitt?] to "Mr. Powers". Box 2, folder 100. 1903 Apr 16. https://collections.library.yale.edu/catalog/2053734.

APA, 6th edition

Whitman, Walt, 1819-1892. (["Box 2, folder 100"])(1903 Apr 16)[Keller, E.[lizabeth Leavitt?] to "Mr. Powers"]. https://collections.library.yale.edu/catalog/2053734.