推荐引擎初探
http://tiny4.org/blog/2011/05/recommend-enginee/
http://www.ibm.com/developerworks/cn/web/1103_zhaoct_recommstudy1/index.html
http://www.ibm.com/developerworks/cn/web/1103_zhaoct_recommstudy2/index.html
http://www.ibm.com/developerworks/cn/web/1103_zhaoct_recommstudy3/index.html
