Senior, Clarence. Strangers--Then Neighbors: From Pilgrims to Puerto Ricans. New York: Freedom Books, 1961

Senior, Clarence. Strangers--Then Neighbors: From Pilgrims to Puerto Ricans. New York: Freedom Books, 1961, Volume: Gilbert C500. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/527635 Accessed December 27, 2025.