MLA

Matthias, Blanche (1887-1983). Korea. Box 11, folder 198. n.d.. https://collections.library.yale.edu/catalog/33353213.

APA, 6th edition

Matthias, Blanche (1887-1983). (["Box 11, folder 198"])(n.d.)[Korea]. https://collections.library.yale.edu/catalog/33353213.