Statistical properties of business firms structure and growth K. Matia, Dongfeng Fu, S. V. Buldyrev, F. Pammolli, M. Riccaboni and H. E. Stanley Europhys. Lett., 67 3 (2004) 498-503 Published online: 01 July 2004 DOI: 10.1209/epl/i2004-10070-4