In Copenhagen, Denmark
MLA
Lindbergh, Charles A. (Charles Augustus), 1902-1974. In Copenhagen, Denmark. Box 14, folder 3. 1933 August 26-September 4. https://collections.library.yale.edu/catalog/10013267.
APA, 6th edition
Lindbergh, Charles A. (Charles Augustus), 1902-1974. (["Box 14, folder 3"])(1933 August 26-September 4)[In Copenhagen, Denmark]. https://collections.library.yale.edu/catalog/10013267.