Torres, D.F., Boldt, E., Hamilton, T., Loewenstein, M.
    "Nearby quasar remnants and ultra-high cosmic rays"
     Phys. Rev. D 66, 023001 (2002)   (Download PDF file)
    Related Sky and Telescope Article

Günter Sigl
    "Ultrahigh-Energy Cosmic Rays: Physics and Astrophysics at Extreme Energies"
      Science  vol. 291 January 5, 2001, pp. 73-79. (Download PDF file)
 

James Trefil
    "Discovering Cosmic Rays"
      Astronomy Magazine  January 2001, pp. 36-39.
 

Ivan Semeniuk
    "Showered in Mystery"
      Astronomy Magazine  January 2001, pp. 43-47.
 

Nagano, M.  and Watson, A.A.
     "Observations and implications of the ultrahigh-energy cosmic rays"
        Rev. Mod. Phys. 72, 689-732 (2000).  (Download PDF file)

Cronin JW
    "Cosmic rays: the most energetic particles in the universe"
     REV MOD PHYS 71: S165-S172 Sp. Iss. SI MAR 1999  (Download PDF file)
 

AGASA results:
     Science, vol. 281, August 14, 1998, page 893.
 

Cronin, J.W., Gaisser T.K., Swordy S.P.
    "Cosmic rays at the energy frontier"
     SCI AM 276: (1) 44-49 JAN 1997