Chris H. Q. Ding Xiaofeng He Parry Husbands Hongyuan Zha Horst D. Simon PageRank, HITS and a unified framework for link analysis. 353-354 2002 conf/sigir/2002 SIGIR http://doi.acm.org/10.1145/564376.564440 db/conf/sigir/sigir2002.html#DingHHZS02