Wei Zhang Lifeng Jia Clement T. Yu Weiyi Meng Improve the effectiveness of the opinion retrieval and opinion polarity classification. 1415-1416 2008 CIKM http://doi.acm.org/10.1145/1458082.1458309 conf/cikm/2008 db/conf/cikm/cikm2008.html#ZhangJYM08