The Pierre Auger Observatory I: The Cosmic Ray Energy Spectrum and   Related Measurements
  Studies of the cosmic ray energy spectrum at the highest energies with the Pierre Auger Observatory 
The Pierre Auger Collaboration: P. Abreu, M. Aglietta, E.J. Ahn,   I.F.M. Albuquerque, D. Allard, I. Allekotte, J. Allen, P....
astro-ph.HE hep-ex