Quantitative imaging of dynamic structure and function of the heart, lungs and circulation by computerized reconstruction and subtraction techniques. - Richard A. Robb; Erik L. Ritman; James F. Greenleaf; Ralph E. Sturm; Gabor T. Herman; Peter A. Chevalier; Hsun K. Liu; Earl H. Wood (SIGGRAPH, 1976)

A simple shading for computer displayed surfaces. - Gabor T. Herman; Hsun K. Liu (Acta Cybern., 1978)