1. Levskovskii, V.N.: Sov. J. Nucl. Phys.18, 361 (1974)
2. Eder, G., Winkler, G., Hille, P.: Z. Phys.253, 335 (1972)
3. Kumabe, I., Fukuda, K.: NEANDC (J)-56/U, 45 (1978)
4. Bychkov, V.M., Manokhin, V.N., Pashchenko, A.B., Plyaskin, V.I.: INDC (CCP)-146/LJ (1979)
5. Ait-Tahar, S.: M.Sc. Thesis Oxford 1986