Incompatibility networks as models of scale-free small-world graphs Zhongzhi Zhang, Shuigeng Zhou, Tao Zou, Lichao Chen and Jihong Guan Eur. Phys. J. B, 60 2 (2007) 259-264 Published online: 08 December 2007 DOI: 10.1140/epjb/e2007-00344-7