Ennan Zhai Huiping Sun Sihan Qing Zhong Chen SpamClean: Towards Spam-Free Tagging Systems. 429-435 2009 CSE (4) http://dx.doi.org/10.1109/CSE.2009.154 conf/cse/2009 db/conf/cse/cse2009-4.html#ZhaiSQC09