coupure GZK
1997 / [Search and Discovery] Auger Project Seeks to Study Highest Energy Cosmic Rays / Bertram Schwarzschild / Physics Today 50 (1997) p. 19 [doi]
1998 / [Search and Discovery] Giant Air Shower Array Shows Cosmic-Ray Spectrum Violating Greisen Cutoff / Bertram Schwarzschild / Physics Today 51 (1998) p. 19 [doi]
2007 / [Search and Discovery] Fluorescence Telescopes Observe the Predicted Ultrahigh-Energy Cutoff of the Cosmic-Ray Spectrum / Bertram Schwarzschild / Physics Today 60 (2007) p. 17 [doi]
2008 / [Search and Discovery] The Highest-Energy Cosmic Rays Appear to Come from Nearby Active Galactic Nuclei / Bertram Schwarzschild / Physics Today 61 (2008) p. 16 [doi]