Bayer, B. E.,  "An Optimum Method for Two-Level Rendition of Continuous Tone 
Pictures," IEEE 1973 International Conference on Communications, Conf. Rec., 
pp. 26-11 to 26-15.

Foley, J. D. and Andries Van Dam.  Fundamentals of Interactive Computer 
Graphics.  Reading, MA: Addison-Wesley, 1982.

Heckbert, Paul,  "Color Image Quantization for Frame Buffer Display," Computer
Graphics, vol. 16, pp. 297-307, 1982.  (SIGGRAPH 82)

Jarvis, J. F., C. N. Judice, and W. H. Ninke,  "A Survey of Techniques for the
Display of Continuous Tone Pictures on Bi-Level Displays."  Computer Graphics 
and Image Processing,  vol. 5, no. 1, (March 1976), pp. 13-40.

Kuto, Sachio,  "Continuous Color Presentation Using a Low-Cost Ink Jet 
Printer," Proc. Computer Graphics Tokyo 84, 24-27 April, 1984, Tokyo, Japan.

Mitchell, W. J., Liggett, R. S. and Kvan, T.  The Art of Computer Graphics 
Programming.  New York: Van Nostrand Reinhold Co., 1987.

Newman, William M., and Robert F. S. Sproull.  Principles of Interactive 
Computer Graphics.  2nd edition.  New York: McGraw-Hill, 1979.

Pavlidis, Theo.  Algorithms for Graphics and Image Processing. Rockville, MD:
Computer Science Press, 1982.

Rogers, David F.  Procedural Elements for Computer Graphics.  New York:  
McGraw-Hill, 1985.

Rogers, David F., and J. A. Adams.  Mathematical Elements for Computer 
Graphics.  New York:  McGraw-Hill, 1976.