Derr, Tilghman (1843-1915), Ms. Coll. 254. E&R Library & Archives.
Derr, Tilghman (1843-1915), Ms. Coll. 254. E&R Library & Archives. https://erhistoricalsociety.libraryhost.com/repositories/2/resources/3463 Accessed July 27, 2025.
