OpenGL Multipipe SDK: A Toolkit for Scalable Parallel Rendering. - Praveen Bhaniramka; Philippe C. D. Robert; Stefan Eilemann (IEEE Visualization, 2005)

Hybrid ray tracing - ray tracing using gpu-accelerated image-space methods. - Philippe C. D. Robert; Severin Schoepke; Hanspeter Bieri (GRAPP (GM/R), 2007)