MLA

Gibbs, J. Willard (Josiah Willard), 1839-1903. Statistical Mechanics: Examples of Intermolecular Action - autograph manuscript notes.. Box 11, folder 224. undated. https://collections.library.yale.edu/catalog/10050257.

APA, 6th edition

Gibbs, J. Willard (Josiah Willard), 1839-1903. (["Box 11, folder 224"])(undated)[Statistical Mechanics: Examples of Intermolecular Action - autograph manuscript notes.]. https://collections.library.yale.edu/catalog/10050257.