Tuan-Fang Fan Churn-Jung Liau Duen-Ren Liu A Bipolar Interpretation of Fuzzy Decision Trees. 109-123 2008 Data Mining: Foundations and Practice http://dx.doi.org/10.1007/978-3-540-78488-3_6 series/sci/2008-118 db/series/sci/sci118.html#FanLL08