Cite

Paz, Octavio. "Hymn Among Ruins"

MLA

Williams, William Carlos, 1883-1963. Paz, Octavio. "Hymn Among Ruins". Box 68, folder 1419. undated. https://collections.library.yale.edu/catalog/11394796.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 68, folder 1419"])(undated)[Paz, Octavio. "Hymn Among Ruins"]. https://collections.library.yale.edu/catalog/11394796.