Frederick W. Blackwell, Robert H. Anderson. An on-line symbolic mathematics system using hand-printed two-dimensional notation. In Solomon L. Pollack, Thomas R. Dines, Ward C. Sangren, Norman R. Nielsen, William G. Gerkin, Alfred E. Corduan, Len Nowak, James L. Mueller, Joseph Horner III, Pasteur S. T. Yuen, Jeffery Stein, Margaret M. Mueller, editors, Proceedings of the 24th national conference, ACM 1969, USA, 1969. pages 551-557, ACM, 1969. [doi]
Abstract is missing.