1. V. P. Chuprova, S. K. Gerasimova, V. G. Grigoryev, P. A. Krivoshapkin, G. F. Krymsky, V. P. Mamrukova, V. M. Migunov, A. N. Prikhodko, G. V. Shafer, G. V. Skripin, Ye. Ye. Sorokin, S. A. Starodubtsev, and V. E. Timofeev, Adv. Space Res. 44, 1200 (2009).
2. G. V. Shafer and Yu. G. Shafer, Presitional Measurements of Cosmic Rays in Yakutsk (Nauka, Novosibirsk, 1984) [in Russian].
3. C. J. Hatton and H. Carmichael, Can. J. Phys. 42, 2443 (1964).
4. V. G. Grigoryev, S. A. Starodubtsev, G. F. Krymsky, P. A. Krivoshapkin, V. E. Timofeev, A. N. Prikhodko, and A. Ya. Karmadonov, in Proceeding of the 32nd Internation Cosmic Ray Conference, Beijing, China, 2011, Vol. 11, p. 257.
5. P. A. Krivoshapkin, G. F. Krymsky, A. I. Kuzmin, and G. V. Skripin, Geomag. Aeron. 9, 228 (1969).