Irina Botan Peter M. Fischer Daniela Florescu Donald Kossmann Tim Kraska Rokas Tamosevicius Extending XQuery with Window Functions. 75-86 2007 conf/vldb/2007 VLDB http://www.vldb.org/conf/2007/papers/research/p75-botan.pdf db/conf/vldb/vldb2007.html#BotanFFKKT07