MLA

Schletter, Annie, 1858-1944. Gaus?, M. A. "To My Sister Rosetta" Poem, 2 holograph copies, signed. Box 2, folder 73. 1840 Jan 7. https://collections.library.yale.edu/catalog/17453748.

APA, 6th edition

Schletter, Annie, 1858-1944. (["Box 2, folder 73"])(1840 Jan 7)[Gaus?, M. A. "To My Sister Rosetta" Poem, 2 holograph copies, signed]. https://collections.library.yale.edu/catalog/17453748.