MLA

Clark, William, 1770-1838, Lewis, Meriwether, 1774-180. Printed form used by Captains during the Expedition: "Thomas Jefferson, President of the United States of America. From the powers vested in us and [blank] by the above authority: To all who shall see these presents, Greeting: Know ye, that from the spec. Box 2 | Folder 59r. undated. https://collections.library.yale.edu/catalog/2002514.

APA, 6th edition

Clark, William, 1770-1838, & Lewis, Meriwether, 1774-180. (["Box 2 | Folder 59r"])(undated)[Printed form used by Captains during the Expedition: "Thomas Jefferson, President of the United States of America. From the powers vested in us and [blank] by the above authority: To all who shall see these presents, Greeting: Know ye, that from the spec]. https://collections.library.yale.edu/catalog/2002514.