MLA

Lindbergh, Charles A. (Charles Augustus), 1902-1974. In Boston, Massachusetts. Box 6, folder 11. 1927 July 22. https://collections.library.yale.edu/catalog/10013217.

APA, 6th edition

Lindbergh, Charles A. (Charles Augustus), 1902-1974. (["Box 6, folder 11"])(1927 July 22)[In Boston, Massachusetts]. https://collections.library.yale.edu/catalog/10013217.