Donglin Cao Hongbo Xu Shuo Bai Xueqi Cheng Shaozi Li A Novel Language Model Based on Cognition Attention Attenuation in Web Retrieval. 676-682 2008 Web Intelligence http://dx.doi.org/10.1109/WIIAT.2008.19 conf/webi/2008 db/conf/webi/webi2008.html#CaoXBCL08