1. 2. International Organisation for Standardisation (ISO) ,Graphical Kernel Sysrem for Three Dimensions (GKS-3D). ISO IS 8805, 1988, Functional Description. ISO IS 8806-1, 1988 , Language Bindings: (Part 1) - Fortran.
2. 3. International Organisation for Standardisation (ISO). Programmer's Hierarchical Graphics System (PHIGS), ISO DIS 9592-1, 1988, Functional Description. ISO DIS 9593-1, 1988, Language Bindings: (Part I) - Fortran.
3. Are PHIGS and GKS Necessainly Incompatible?
4. 5. J. Steinhart , GKS Lelvel 3 Proposal. ISO TC97/SC5/WG2 N309 (1984 ).