1998, Nature (London), 391, 59, 10.1038/34139
1998, Nature (London), 391, 62, 10.1038/34145
1997, Nature (London), 386, 474, 10.1038/386474a0
1997, Science, 275, 1922, 10.1126/science.275.5308.1922
1998, Nature (London), 393, 49, 10.1038/29954
1995, Chem. Phys. Lett., 243, 49, 10.1016/0009-2614(95)00825-O
1994, Science, 266, 1218, 10.1126/science.266.5188.1218
1998, Chem. Phys. Lett., 287, 53, 10.1016/S0009-2614(98)00144-4
1997, Phys. Rev. B, 55, R4921, 10.1103/PhysRevB.55.R4921
1998, Science, 280, 1744, 10.1126/science.280.5370.1744