MLA

Henri, Robert, 1865-1929. Artists Pigments notebook II. Box 25, folder 591-596. 1916-19. https://collections.library.yale.edu/catalog/17029592.

APA, 6th edition

Henri, Robert, 1865-1929. (["Box 25, folder 591-596"])(1916-19)[Artists Pigments notebook II]. https://collections.library.yale.edu/catalog/17029592.