MLA

Lindbergh, Charles A. (Charles Augustus), 1902-1974. Feydy, Anne Spencer Lindbergh, family. Box 29, folder 6. 1964-1974. https://collections.library.yale.edu/catalog/10021417.

APA, 6th edition

Lindbergh, Charles A. (Charles Augustus), 1902-1974. (["Box 29, folder 6"])(1964-1974)[Feydy, Anne Spencer Lindbergh, family]. https://collections.library.yale.edu/catalog/10021417.