1. Charles Kittel, Introduction to Solid State Physics, (Wiley, New York, 1953), page 52. (This definition is deleted in later editions.)
2. Ronald D. Kriz and Hassel M. Ledbetter, “Elastic Representation Surfaces of Unidirectional Graphite/Epoxy Composites,” In Recent Advances in Composites in the United States and Japan: ASTM Special Technical Testing Publication 864, Edited by J. R. Vinson and M. Taya, ( American Society for Testing and Materials, Philadelphia, Pennsylvania, 1985).
3. M.J.P. Musgrave, Crystal Acoustics, (Holden-Day, San Francisco, 1970).
4. Robert E. Green, Jr., Ultrasonic Investigation of Mechanical Properties, in Treatise on Materials Science and Technology, vol. 3, edited by Herbert Herman, (Academic Press, New York, 1973).
5. David F. Rogers, Procedural Elements for Computer Graphics, (McGraw Hill, New York, 1985).