MLA

Whitman, Walt, 1819-1892. "Thou Who Hast Slept All Night Upon the Storm," galley proof, corrected, with proofreaders' marks. Box 1, folder 7. n.d.. https://collections.library.yale.edu/catalog/2053641.

APA, 6th edition

Whitman, Walt, 1819-1892. (["Box 1, folder 7"])(n.d.)["Thou Who Hast Slept All Night Upon the Storm," galley proof, corrected, with proofreaders' marks]. https://collections.library.yale.edu/catalog/2053641.