1940, Proc. R. Ir. Acad. Sect. A, Math. Astron. Phys. Sci., 46, 183
1941, Proc. R. Ir. Acad., Sect. A, 47, 53
1951, Rev. Mod. Phys., 23, 21, 10.1103/RevModPhys.23.21
1995, J. Chem. Phys., 103, 3006, 10.1063/1.470489
1969, Phys. Rev., 184, 1231, 10.1103/PhysRev.184.1231
1970, Ann. Phys. (N.Y.), 58, 76, 10.1016/0003-4916(70)90240-X
1961, Phys. Rev., 124, 483, 10.1103/PhysRev.124.483
1965, J. Chem. Phys., 43, 186, 10.1063/1.1701484
1973, Phys. Rev. D, 8, 3487
1972, Phys. Rev. D, 7, 1701
1981, J. Math. Phys., 22, 1983, 10.1063/1.525144
1973, J. Math. Phys., 14, 1190, 10.1063/1.1666462
1978, Proc. R. Soc. A, 364, 265
1994, Phys. Lett. A, 194, 343, 10.1016/0375-9601(94)91291-2
1969, Phys. Lett. B, 30, 656, 10.1016/0370-2693(69)90087-2
1970, Phys. Lett. B, 32, 631, 10.1016/0370-2693(70)90564-2
1971, Nuovo Cimento B, 4, 313, 10.1007/BF02728240
1984, J. Phys. A, 17, 547, 10.1088/0305-4470/17/3/016
1996, Phys. Rev. A, 54, 81, 10.1103/PhysRevA.54.81
1982, Phys. Lett. A, 88, 4, 10.1016/0375-9601(82)90409-1
1978, Phys. Lett. A, 65, 87, 10.1016/0375-9601(78)90580-7
1987, J. Phys. A, 20, 5541, 10.1088/0305-4470/20/16/028
1978, Chem. Phys. Lett., 55, 303, 10.1016/0009-2614(78)87024-9
1997, J. Math. Phys., 38, 639, 10.1063/1.531857
1975, J. Math. Phys., 16, 1945, 10.1063/1.522747
1975, J. Chem. Phys., 63, 3744, 10.1063/1.431855
1980, J. Math. Phys., 21, 2780, 10.1063/1.524398
1982, J. Phys. A, 15, 3679, 10.1088/0305-4470/15/12/019
1994, J. Math. Phys., 35, 6244, 10.1063/1.530673
1996, Phys. Rev. A, 53, 1330, 10.1103/PhysRevA.53.1330
1933, Z. Phys., 83, 143, 10.1007/BF01331132