MLA

McGlashan, E. L. (Everitt Lynn), 1911-1978. Boyd, William of Lancaster, Pennsylvania. Record of registration for three mulatto children and their mother (C22). Box 1, folder 31. 1789 Mar 31. https://collections.library.yale.edu/catalog/17321347.

APA, 6th edition

McGlashan, E. L. (Everitt Lynn), 1911-1978. (["Box 1, folder 31"])(1789 Mar 31)[Boyd, William of Lancaster, Pennsylvania. Record of registration for three mulatto children and their mother (C22)]. https://collections.library.yale.edu/catalog/17321347.