Statistical properties of business firms structure and growthK. Matia, Dongfeng Fu, S. V. Buldyrev, F. Pammolli, M. Riccaboni and H. E. StanleyEurophys. Lett., 67 3 (2004) 498-503DOI: https://doi.org/10.1209/epl/i2004-10070-4