1. Arnell, S.E.: Arkiv Fysik 21 (1962) 177.
2. Katsanos, A.A., Huizenga, J.R.: Phys. Rev. 159 (1967) 931.
3. Okorokov, V.V., Serezhin, V.M., Smotryaev, V.A., Tolchenkov, D.L., Trostin, I.S., Cheblukov, Y.N.: Program and Theses, Proc. 18th Ann. Conf. Nucl. Spectr. and Struct. of At. Nucl., Riga, p. 118 (1968).
4. Cujec, B., Szoghy, I.M.: Phys. Rev. 179 (1969) 1060.
5. Peterson, R.J.: Ann. Phys. (N.Y.) 53 (1969) 40.