Colburn’s first lessons: Intellectual arithmetic, upon the inductive method of instruction, 660 - Chandler Collection no. 2, Volume: Archives Chandler Collection no. 2. Clarion University Archives.

Colburn’s first lessons: Intellectual arithmetic, upon the inductive method of instruction, 660 - Chandler Collection no. 2, Volume: Archives Chandler Collection no. 2. Clarion University Archives. http://as-clarion.klnpa.org/repositories/2/resources/913 Accessed December 24, 2025.