Hurwitz, A., Citron, J. P., and Yeaton, J. B., "GRAF: Graphic Addition to FORTRAN", pp553-557

[AFIPS] Proceedings of the 1967 Spring Joint Compu (1967) [AFIPS] Proceedings of the 1967 Spring Joint Computer Conference, April 18-20, Atlantic City, N. J. SJCC 30  

Languages mentioned GRAF {1967} GRaphic Additions to FORTRAN