1. S. Liberman, J. Pinard, H.T. Duong, P. Juncar, J.L. Vialle, P. Jacquinot, G. Huber, F. Touchard, S. Büttgenbach, A. Pesnelle, C. Thibault, R. Klapisch and the ISOLDE Collaboration, C.R. Acad. Sci. Paris B286(1978)253; S. Liberman, J. Pinard, H.T. Duong, P. Juncar, P. Pillet, J.L. Vialle, P. Jacquinot, F. Touchard, S. Büttgenbach, C. Thibault, M. de Saint-Simon, R. Klapisch, A. Pesnelle and G. Huber, Phys. Rev. A22(1980)2732; A. Coc, C. Thibault, F. Touchard, H.T. Duong, P. Juncar, S. Liberman, J. Pinard, J. Lermé, J.L. Vialle, S. Büttgenbach, A.C. Mueller, A. Pesnelle and the ISOLDE Collaboration, Phys. Lett. B163(1985)66; H.T. Duong, P. Juncar, S. Liberman, A.C. Mueller, R. Neugart, E.W. Otten, B. Peuse, J. Pinard, H.H. Stroke, C. Thibault, F. Touchard, J.L. Vialle, K. Wendt and the ISOLDE Collaboration, Europhys. Lett. 3 (1987)175; E. Arnold, W. Borchers, M. Carré, H.T. Duong, P. Juncar, J. Lermé, S. Liberman, W. Neu, R. Neugart, E.W. Otten, M. Pellarin, A. Pesnelle, J. Pinard, J.L. Vialle, K. Wendt and the ISOLDE Collaboration, J. Phys. B22(1989)L391; E. Arnold, W. Borchers, H.T. Duong, P. Juncar, J. Lermé, P. Lievens, W. Neu, R. Neugart, M. Pellarin, J. Pinard, J.L. Vialle, K. Wendt and the ISOLDE Collaboration, J. Phys. B23 (1990)3511.
2. S.V. Andreev, V.S. Letokhov and V.I. Mishin, JETP Lett. 43(1986)736; S.V. Andreev, V.S. Letokhov and V.I. Mishin, Phys. Rev. Lett. 59(1987)1169; S.V. Andreev, V.I. Mishin and V.S. Letokhov, J. Opt. Soc. Am. B5(1988)2190.
3. V.A. Dzuba, V.V. Flambaum and O.P. Sushkov, Phys. Lett. A95(1983)230; V.A. Dzuba, V.V. Flambaum and O.P. Sushkov, J. Phys. B17(1984)1953.
4. W.J. Marciano and J.L. Rosner, Phys. Rev. Lett. 65(1990)2963.
5. S.A. Blundell, W.R. Johnson and J. Sapirstein, Phys. Rev. A38(1988)4961.