MLA

Lindbergh, Anne Morrow, 1906-2001. "Flying Around the North Atlantic" (article) National Geographic Magazine. Box 162, folder 452. 1934 September. https://collections.library.yale.edu/catalog/10016666.

APA, 6th edition

Lindbergh, Anne Morrow, 1906-2001. (["Box 162, folder 452"])(1934 September)["Flying Around the North Atlantic" (article) National Geographic Magazine]. https://collections.library.yale.edu/catalog/10016666.