Cite

Sitting on rock writing in notebook, [ca. 1893-94] (copy) (2 prints)

MLA

O'Neill, Eugene, 1888-1953. Sitting on rock writing in notebook, [ca. 1893-94] (copy) (2 prints). Box 108, folder 1809. n.d.. https://collections.library.yale.edu/catalog/2013201.

APA, 6th edition

O'Neill, Eugene, 1888-1953. (["Box 108, folder 1809"])(n.d.)[Sitting on rock writing in notebook, [ca. 1893-94] (copy) (2 prints)]. https://collections.library.yale.edu/catalog/2013201.