1. Optical Data, Inc.; U.S. Patent 4,719,615; 1988.
2. J.M. Halter and N.E. Iwamoto, SPIE Symposium Proceedings No. 899, January 1988.
3. Michael A. Cochran, John H. Dunbar, Alastair M. North, and Richard A. Pethrick, JCS Faraday II, 70, 215 (1974).
4. Alastair M. North, Richard A. Pethrick and Ian Rhoney, JCS Faraday II, 70, 223 (1974).
5. W. P. Slichter; NMR (1971) v. 4, p. 209 ff; ed. P. Diehl, E. Fluck, R. Kosfeld, 1971.