1. J. Blons, C. Mazur and D. Paya, Phys. Rev. Lett. 35 (1975) 1749.
2. J. Blons, C. Mazur, D. Paya, M. Ribrag and H. Weighmann, Winter College on Nuclear Physics and Reactors, Bormio, Italy, 1980.
3. S.B. Earmagambetov and G.N. Smirenkin, Sov. J. Nucl. Phys. 11 (1970) 646.
4. J. Caruana, J.W. Boldeman and R.L. Walsh, Nucl. Phys. A285 (1977) 205.
5. N. Dyachenko, B.O. Kuzminov, V.F. Mitrofanof and Sergachev, Sov. J. Nucl. Phys. 26 (1977) 365.