1. M. Levinson: Introduction to Nonlinear Laser Spectroscopy ( Academic, New York 1982 )
2. For example, D. H. Auston, K. B. Eisenthal (eds): Ultrafast Phenomena IV, Springer Ser. Chem. Phys. Vol. 38 ( Springer, Berlin, Heidelberg 1984 )
3. J. A. Giordmaine, R. C. Miller: Phys. Rev. Lett. 14, 973 (1965)
4. Y.-R. Shen (ed.): Nonlinear Infrared Generation, Topics Appl. Phys., Vol. 16 ( Springer, Berlin, Heidelberg 1977 )
5. F. P. Schäfer, W. Schmidt: Z. Naturforschg. 19a, 1019 (1964)