International Conference Tsubasa Takahashi and Hiroyuki Kitagawa: "A Ranking Method for Web Search using Social Bookmarks", Proc. 14th International Conference on Database Systems for Advanced Applications (DASFAA2009), pp.585-589, Brisbane, Australia, April 21-23, 2009. Tsubasa Takahashi and Hiroyuki Kitagawa: "S-BITS: Social Bookmarking Induced Topic Search", Proc. 9th International Conference o