MLA

Stenzel, Franz (1906-1998). "Nanaimo River, Vancouvers Island." Watercolor, 23.9 x 34.2 cm on sheet 30.4 x 45.4 cm.. Box 4, folder 61. n.d.. https://collections.library.yale.edu/catalog/10869219.

APA, 6th edition

Stenzel, Franz (1906-1998). (["Box 4, folder 61"])(n.d.)["Nanaimo River, Vancouvers Island." Watercolor, 23.9 x 34.2 cm on sheet 30.4 x 45.4 cm.]. https://collections.library.yale.edu/catalog/10869219.