Full key to a practical system of book-keeping by single and double entry, 660 - Chandler Collection no. 7, Volume: Archives Chandler Collection no. 7. Clarion University Archives.

Full key to a practical system of book-keeping by single and double entry, 660 - Chandler Collection no. 7, Volume: Archives Chandler Collection no. 7. Clarion University Archives. http://as-clarion.klnpa.org/repositories/2/resources/988 Accessed December 25, 2025.