James DuShane, "DuShane's Number Chart for Busy-Work", OBD004, Folder: OBD004. Rare Books and Manuscripts.
James DuShane, "DuShane's Number Chart for Busy-Work", OBD004, Folder: OBD004. Rare Books and Manuscripts. https://archives.isl.lib.in.us//repositories/2/resources/1219 Accessed May 06, 2024.