MLA

Henri, Robert, 1865-1929. Correspondence. Box 17, folder 412. 1918 Aug-Sep. https://collections.library.yale.edu/catalog/33486014.

APA, 6th edition

Henri, Robert, 1865-1929. (["Box 17, folder 412"])(1918 Aug-Sep)[Correspondence]. https://collections.library.yale.edu/catalog/33486014.