[Gold?] coin
MLA
Whitman, Walt, 1819-1892. [Gold?] coin. Box 17, folder 272. n.d.. https://collections.library.yale.edu/catalog/2012036.
APA, 6th edition
Whitman, Walt, 1819-1892. (["Box 17, folder 272"])(n.d.)[[Gold?] coin]. https://collections.library.yale.edu/catalog/2012036.