1. Williamson, C.F., Boyot, J.-P., Picard, J.: CEA-R3042 (1966)
2. Jahn, P.: Internal Report, Institute for Nuclear Physics, KFA J�lich (1972)
3. Jahn, P., Probst, H.-J., Djaloeis, A., Davidson, W.F., Mayer-B�ricke, C.: Nucl. Phys. A209, 333 (1973)
4. Kavanagh, T.M., Bell, R.E.: Can. J. Phys.39, 1172 (1961)
5. Alderlisten, C., Bousshid, O., Jahn, P., Probst, H.-J., Mayer-B�ricke, C.: to be published