Schaeffer, Isaac Merkel (1867-1929), Ms. Coll. 346. E&R Library & Archives.
Schaeffer, Isaac Merkel (1867-1929), Ms. Coll. 346. E&R Library & Archives. https://erhistoricalsociety.libraryhost.com/repositories/2/resources/3555 Accessed July 28, 2025.
