Schrödinger, E.: Naturwissenschaften 14, 137 (1926)
Alber, G., Zoller, P.: Phys. Rep. 199, 231 (1991) for a review, and references therein
Yeazell, J.A., Mallieu, M., Stroud Jr., C.R.: Phys. Rev. Lett. 64, 2007 (1990)
Nauenberg, M.: J. Phys. B 23, L 385 (1990)
Yeazell, J.A., Stroud Jr., C.R.: Phys. Rev. A 43, 5153 (1991)
Meacher, D.R., Meyler, P.E., Hughes, I.G., Ewart, P.: J. Phys. B 24, L 63 (1991)
Lena, C., Delande, D., Gay, J.C.: Europhys. Lett. 15, 697 (1991)
Peres, A.: Phys. Rev. A 47, 5196 (1993)
Braun, P.A., Savichev, V.I.: Phys. Rev. A 49, 1704 (1994)
Bluhm, R., Kostelecky, V.A.: Phys. Rev. A 50, R4445 (1994)
Ehlich, R., Campbell, E.E.B., Knospe, O., Schmidt, R.: Z. Phys. D 28, 153 (1993)
Wang, L.S., Conceicao, J.J., Jin, C.M., Smalley, R.E.: Chem. Phys. Lett. 182, 5 (1991)
Yabana, K., Bertsch, G.F.: Phys. Scr. 48, 633 (1993)
Ulmer, G., Campbell, E.E.B., Kühnle, R., Busmann, H.-G., Hertel, I.V.: Chem. Phys. Lett. 182, 114 (1991); Yeretzian, C., Hansen, K., Diederich, F., Whetten R.L.: Nature 359, 44 (1992)
Coe, J.: private communication
Knospe, O., Schmidt, R.: to be published