Florida Estrella Chiara Del Frate Tamas Hauer Richard McClatchey Mohammed Odeh Dmitri Rogulin S. Roberto Amendolia David Schottlander Tony Solomonides Ruth Warren http://arxiv.org/abs/cs.DB/0402009 2004 CoRR cs.DB/0402009 db/journals/corr/corr0402.html#cs-DB-0402009 informal publication