Zhaojie Xia Li Guo Chunyan Liang Xiaoxia Li Zhangyuan Yang Focused Crawling for Retrieving Chemical Information. 433-438 2008 Innovations in Hybrid Intelligent Systems http://dx.doi.org/10.1007/978-3-540-74972-1_56 series/asc/2008-44 db/series/asc/asc44.html#XiaGLLY08