See also: E.M. Belenov, V.A. Isakov, A.N. Oraevskii, V.I. Romanenko, N.G. Basov, V.S. Letokhov
PACS: 31.30.Gs, 33.80.Gj, 33.10.Gx, 28.60.+s, 42.60.Kg