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2. Forward heavy-flavour production in pp collisions at LHC and intrinsic quark components in protons
3. The pierre auger collaboration;Nucl. Instr. and Meth. A,2015
4. A. Aab et al., [Pierre Auger Collaboration], The pierre auger observatory upgrade - preliminary design report, arXiv:1604.03637 [astro-ph.IM]. See also www.auger.org/augerprime.
5. S.J. Sciutto, AIRES, a system for air shower simulation and analysis, See www2.fisica.unlp.edu.ar/aires.