Measurement of the Flux of Ultrahigh Energy Cosmic Rays from Monocular Observations by the High Resolution Fly's Eye Experiment
  Abbasi, R.U.; Abu-Zayyad, T.; et al.; Physical Review Letters, vol. 92 num. 15, 16 Apr. 2004

First Observation of the Greisen-Zatsepin-Kuzmin Suppression
  Abbasi, R.U.; Abu-Zayyad, T.; et al.; Physical Review Letters, vol. 100 num. 10 Mar. 2008

Indications of Proton-Dominated Cosmic-Ray Composition above 1.6 EeV
  Abbasi, R.U.; Abu-Zayyad, T.; et al.; Physical Review Letters, vol. 104 num. 16 Apr. 2010

Data Supplement to "Indications of Proton-Dominated Cosmic-Ray Composition above 1.6 EeV"
  Abbasi, R.U.; Abu-Zayyad, T.; et al.; Physical Review Letters, vol. 104 num. 16 Apr. 2010