MLA

Lockwood, Samuel, 1803-1893. Official letterbook. Box 1, folder 15. 1858-1861. https://collections.library.yale.edu/catalog/32529354.

APA, 6th edition

Lockwood, Samuel, 1803-1893. (["Box 1, folder 15"])(1858-1861)[Official letterbook]. https://collections.library.yale.edu/catalog/32529354.