Cite

"Essays for Martians"

MLA

Williams, William Carlos, 1883-1963. "Essays for Martians". Box 40, folder 1020. undated. https://collections.library.yale.edu/catalog/17049578.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 40, folder 1020"])(undated)["Essays for Martians"]. https://collections.library.yale.edu/catalog/17049578.