Ed Anson. The semantics of graphical input. In Thomas A. DeFanti, Bruce H. McCormick, Bary W. Pollack, Norman I. Badler, S. H. Chasen, editors, Proceedings of the 6th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH 1979, Chicago, Illinois, USA, August 8-10, 1979. pages 113-120, ACM, 1979. [doi]
Abstract is missing.