MLA

Lindbergh, Charles A. (Charles Augustus), 1902-1974. With Jim Newton and Anne Morrow Lindbergh. Box 17, folder 6. 1940 January 21. https://collections.library.yale.edu/catalog/10011803.

APA, 6th edition

Lindbergh, Charles A. (Charles Augustus), 1902-1974. (["Box 17, folder 6"])(1940 January 21)[With Jim Newton and Anne Morrow Lindbergh]. https://collections.library.yale.edu/catalog/10011803.