Competitors’ communities and taxonomy of products according to export fluxes M. Cristelli, A. Tacchella, A. Gabrielli, L. Pietronero, A. Scala and G. Caldarelli Eur. Phys. J. Special Topics, 212 (2012) 115-120 Published online: 17 September 2012 DOI: 10.1140/epjst/e2012-01657-4