Zhijie Cai Enhua Shen Fanji Gu Zhengjie Xu Jiong Ruan Yang Cao A New Two-Dimensional Complexity Measure. 3235-3247 2006 16 I. J. Bifurcation and Chaos 11 http://dx.doi.org/10.1142/S0218127406016756 db/journals/ijbc/ijbc16.html#CaiSGXRC06