Page proofs of newsletters
MLA
Kagan, Paul, 1943-1993. Page proofs of newsletters. Box 15, folder 278-279. n.d.. https://collections.library.yale.edu/catalog/17439164.
APA, 6th edition
Kagan, Paul, 1943-1993. (["Box 15, folder 278-279"])(n.d.)[Page proofs of newsletters]. https://collections.library.yale.edu/catalog/17439164.