1. N.Bloembergen: Nonlinear Optics (Benjamin, New York 1965)
2. P.N.Butcher: Nonlinear Optical Phenomena (Ohio State University, Columbus, Ohio 1865)
3. S.K.Kurtz: In Laser Handbook, ed. by F.T.Arecchi, E.O.Schulz-DuBois (North Holland, Amsterdam 1972) p. 925
4. R.Bechmann, R.F.S.Hearmon, S.K.Kurtz: Landolt-Börnstein, New Series, Group 3, Vol. 2 (Springer, Berlin, Heidelberg, New York 1969) pp. 167–209
5. S.Singh: In Handbook of Lasers, ed. by R.J.Pressley (Chem. Rubber Co., Cleveland, Ohio 1971) p. 489