MLA

Lindbergh, Charles A. (Charles Augustus), 1902-1974. Aero Club of Washington speech. Box 205, folder 385. 1949 December 17. https://collections.library.yale.edu/catalog/10014634.

APA, 6th edition

Lindbergh, Charles A. (Charles Augustus), 1902-1974. (["Box 205, folder 385"])(1949 December 17)[Aero Club of Washington speech]. https://collections.library.yale.edu/catalog/10014634.