MLA

Newell, Peter, 1862-1924. McCormick, Frederick. Box 7, folder 107. 1911-12. https://collections.library.yale.edu/catalog/17181129.

APA, 6th edition

Newell, Peter, 1862-1924. (["Box 7, folder 107"])(1911-12)[McCormick, Frederick]. https://collections.library.yale.edu/catalog/17181129.