MLA

Thoreau, Henry David, 1817-1862. "Travelling," poem, holograph, corrected. Box 1, folder 5. n.d.. https://collections.library.yale.edu/catalog/16867641.

APA, 6th edition

Thoreau, Henry David, 1817-1862. (["Box 1, folder 5"])(n.d.)["Travelling," poem, holograph, corrected]. https://collections.library.yale.edu/catalog/16867641.