In Russia
MLA
McKay, Claude, 1890-1948. In Russia. Box 18, folder 553-554. [ca. 1923]. https://collections.library.yale.edu/catalog/16862298.
APA, 6th edition
McKay, Claude, 1890-1948. (["Box 18, folder 553-554"])([ca. 1923])[In Russia]. https://collections.library.yale.edu/catalog/16862298.