Ricardo A. Baeza-Yates Nivio Ziviani Gary Marchionini Alistair Moffat John Tait SIGIR 2005: Proceedings of the 28th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Salvador, Brazil, August 15-19, 2005 SIGIR ACM 1-59593-034-5 2005 db/conf/sigir/sigir2005.html