MLA

McGlashan, E. L. (Everitt Lynn), 1911-1978. Clagett, Richard. "Public Sale of Negroes," Potters Mart, Charleston, South Carolina, printed broadside (C38). Box 1, folder 38. 1833 Mar 5. https://collections.library.yale.edu/catalog/10191754.

APA, 6th edition

McGlashan, E. L. (Everitt Lynn), 1911-1978. (["Box 1, folder 38"])(1833 Mar 5)[Clagett, Richard. "Public Sale of Negroes," Potters Mart, Charleston, South Carolina, printed broadside (C38)]. https://collections.library.yale.edu/catalog/10191754.