1. Hunsperger, Robert G. Integrated Optics. Study guide, Dept. of Electrical Engineering, University of Deleware, 1978, pp. 3.11–3.14.
2. Schlosser, W. and Unger, H. G. Advances in Microwaves. New York: Academic Press, 1966.
3. Goell, J. E. Bell System Technical journal 48:2071 (1969).
4. Marcatili, E. A. Bell System Technical Journal 53:645 (1974).
5. Ramaswamy, V. Bell System Technical Journal 53:697 (1974).