1. GKS3D, Functional Description, IS 8805.
2. GKS, Graphics Kernel System, TGL 44610.
3. PHIGS+, Programmers Hierarchical Interactive Graphics System, IS 9598—Part 4.
4. ISO, Interim Draft Reference Model for Computer Graphics, ISO/IEC JTC1/SC24/WG1/N49.
5. Graphic Data Processing with GKS;Encarnação,1987