Abdalla, M. S., El-Orany, F. A. A., Peřina st., J. Nonclassical effects in nondegenerate optical parametric symmetric coupler. ISBN 0-8194-3234-2. In: GLASS, A.J., GOODMANN, J.W., eds. Optics for the Next Millenium. Washington: SPIE, 1999, s. 538-539. Proceedings of the International Society for Optical Engineering., 3749.