MLA

Herbst, Josephine, 1892-1969. New Masses. Box 19. 1927-1954, undated. https://collections.library.yale.edu/catalog/10607122.

APA, 6th edition

Herbst, Josephine, 1892-1969. (["Box 19"])(1927-1954, undated)[New Masses]. https://collections.library.yale.edu/catalog/10607122.