MLA

Lindbergh, Anne Morrow, 1906-2001. Hoover, Herbert. Box 9, folder 183. 1940-1944. https://collections.library.yale.edu/catalog/10016113.

APA, 6th edition

Lindbergh, Anne Morrow, 1906-2001. (["Box 9, folder 183"])(1940-1944)[Hoover, Herbert]. https://collections.library.yale.edu/catalog/10016113.