Van Kampen's expansion approach in an opinion formation model M. S. de la Lama, I. G. Szendro, J. R. Iglesias and H. S. Wio Eur. Phys. J. B, 51 3 (2006) 435-442 Published online: 13 June 2006 DOI: 10.1140/epjb/e2006-00232-8