1. A. N. Kushnirenko, Inform. Pis'mo IPM AN USSR, No. 1, July 8, 1966; Preprint No. 1, IPM AN USSR (1969).
2. V. V. Malyarov, Bases of the Theory of the Atomic Nucleus [in Russian], Fizmatgiz, Moscow (1967).
3. B. W. Rolnick and R. M. Thaler, Phys. Rev. Lett.,15, No. 3 (1965).
4. V. S. Barashenkov, Interaction Cross Sections of Elementary Particles [in Russian], Moscow (1966).
5. B. Rossi, Cosmic Rays [Russian translation], Atomizdat, Moscow (1966).