MLA

Speck, William A. (William Alfred), 1864-1928. Chrimehilt. Box 1, folder 31. n.d.. https://collections.library.yale.edu/catalog/2046703.

APA, 6th edition

Speck, William A. (William Alfred), 1864-1928. (["Box 1, folder 31"])(n.d.)[Chrimehilt]. https://collections.library.yale.edu/catalog/2046703.