An Mignon [and] Wonne der Wehmuth
MLA
Speck, William A. (William Alfred), 1864-1928. An Mignon [and] Wonne der Wehmuth. Box 2, folder 25. n.d.. https://collections.library.yale.edu/catalog/2032404.
APA, 6th edition
Speck, William A. (William Alfred), 1864-1928. (["Box 2, folder 25"])(n.d.)[An Mignon [and] Wonne der Wehmuth]. https://collections.library.yale.edu/catalog/2032404.