1. Burke, P.G., Scrutton, D., Tait, M.J.H., Taylor, A.J.: J. Phys. B2, (2), 1155 (1969)
2. Arthurs, A.M., Dalgarno, A.: Proc. Roy. Soc.256A, 540 (1960)
3. Dickinson, A.S., Richards, D.: J. Phys. B7, 1916 (1974)
4. Gordon, R.G.: QCPE Program 187, 1969
5. Bosanac, S., Balint-Kurti, G.G.: Mol. Phys.29, 1797 (1975)