1. B. Antonini et al., Physica,32, No. 1, 119 (1966).
2. F. Sefidvash, in: Proceedings of the Third Conference on Neutron Cross Sections and Technology, Knoxville, Tenn., March 15?17, 1971, Vol. 2, p. 695.
3. S. B. Stepanov et al., in: Proceedings of the Conference ?Neutron Physics,? Izd. Fiz.-Énerg. Inst. (FÉI), Obninsk, Part 4 (1974), p. 257.
4. S. B. Stepanov et al., At. Energ.,37, No. 4, 351 (1974).
5. J. ?ervená et al., Czech. J. Phys., B23, No. 11, 1187 (1973).