Enrichment of primary cosmic rays in heavy nuclei at energies higher than that corresponding to the knee point Vishnevskaya, E. A. ; Kalmykov, N. N. ; Kulikov, G. V. ; Solovjeva, V. I. ; Sulakov, V. P. ; Fomin, Yu. A. ; Khristiansen, G. B. Abstract Publication: Physics of Atomic Nuclei Pub Date: February 1999 Bibcode: 1999PAN....62..265V