1. S. A. Colgate and R. H. White, Astrophys. J. 143, 626 (1966).
2. V. S. Imshennik and D. K. Nadezhin, Zh. Éksp. Teor. Fiz. 63, 1548 (1972) [Sov. Phys. JETP 36, 821 (1973)].
3. V. M. Suslin, M. Yu. Khlopov, V. M. Chechetkin, and V. A. Chuyanov, Astron. Zh. 73(3), 399 (1996) [Astron. Rep. 40, 358 (1996)].
4. M. V. Sazhin, S. D. Ustyugov, and V. M. Chechetkin, Pis'ma Zh. Éksp. Teor. Fiz. 64, 817 (1996) [JETP Lett. 64, 871 (1996)].
5. V. M. Suslin, S. D. Ustyugov, and G. P. Churkina, Preprint No. 70, IPM im. M.V. Keldysha RAN (Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, 1998).