Abraham J., Cronin J. W. et al., Observation of suppression of the Flux of Cosmic Rays above 4x10**19 eV., Phys Rev Letters vol 101, p 061101, (2008).
Abraham J., Cronin J. W. et al, Observation of suppression of the Flux of Cosmic Rays above 4x10**19 eV., Phys Rev Letters vol 101, p 061101, (2008).