Multiplicity spectrum of muon bundles and primary CR composition in the range 1 – 10000 TeV V.B. Petkov, J. Szabelski, A.N. Gaponenko and I. Alikhanov EPJ Web of Conferences, 52 (2013) 09009 Published online: 10 June 2013 DOI: 10.1051/epjconf/20135209009