"Sketches from our Artist's Note-Book."
MLA
Hansen, Bert, 1944-. "Sketches from our Artist's Note-Book.". Box 3, folder 28. 1873 July 12. https://collections.library.yale.edu/catalog/32329501.
APA, 6th edition
Hansen, Bert, 1944-. (["Box 3, folder 28"])(1873 July 12)["Sketches from our Artist's Note-Book."]. https://collections.library.yale.edu/catalog/32329501.