4I.Witten,,E.Frank.WEKA Machine Learning Algorithms in Java[].Data Mining:Practical Machine Learning Tools and Techniques with Java Implementations.2000
5J.Pomerantz.A Linguistic Analysis of Question Taxonomies[].Journal of the American Society for Information Science and Technology.2005
6C.Zhalaing,,P.L.Khanh,,M.Ashesh,et al.Feature Extraction for Learning to Classify Questions[].AI.2004
