Are ultrahigh energy cosmic rays heavy nuclei?

K. Shinozaki, M. Chikawa, M. Fukushima et al., Proc. 28-th ICRC, Tsukuba, 1 (2003) 401 G. Archbold, P.V. Sokolsky et al., Proc. 28-th ICRC, Tsukuba, 1 (2003) 405 S.P. Knurenko, V.A. Kolosov, Z.E. Petrov, I.Ye. Sleptsov, Proc. 27-th ICRC, Hamburg, 1, (2001) 145 J. Linsley, R.J.O. Reid, A.A. Watson, M. Wada, Catalogue of Highest Energy Cosmic Rays, Tokyo, 1 (1980) 97 N.N. Efimov, M.I. Pravdin, A.A. Mikhailov, Proc. 18-th ICRC, Bangalore, 2 (1983) 149 Takeda Winn, 1986, J. Phys. G: Nucl. Phys., 12, 653, 10.1088/0305-4616/12/7/015 N.N. Efimov, T.A. Egorov, A.V. Glushkov et al. Proc. ICRR International Symposium: Astrophysical Aspects of the Most Energetic Cosmic Rays, Kofu, (1990) p. 20 Mikhailov, 2000, JETF Letters, 72, 160, 10.1134/1.1320102