September 27-28, 1804
MLA
Clark, William, 1770-1838. September 27-28, 1804. Box 1, folder 58. 1803-1805. https://collections.library.yale.edu/catalog/2002998.
APA, 6th edition
Clark, William, 1770-1838. (["Box 1, folder 58"])(1803-1805)[September 27-28, 1804]. https://collections.library.yale.edu/catalog/2002998.