See also: R.I. Sokolovskii, B.M. Smirnov, A.V. Eletskii, P.B. Lerner, V.S. Letokhov, E.B. Aleksandrov, G.V. Skrotskii
PACS: 42.50.Pq, 42.50.Hz, 52.25.Os, 52.20.Fs, 52.38.-r, 32.60.+i, 32.70.Jz, 32.50.+d, 32.10.Fn, 32.80.-t, 51.70.+f