http://doi.acm.org/10.1145/211990.212017 db/journals/sigmod/DogacDKOONEHAKKM95.html Asuman Dogac Cevdet Dengi Ebru Kilic Gökhan Özhan Fatma Ozcan Sena Nural Cem Evrendilek Ugur Halici Ismailcem Budak Arpinar Pinar Koksal N. Kesim Sema Mancuhan 56-61 sigmodR/24-3/P056.pdf 1995 24 SIGMOD Record 3 db/journals/sigmod/sigmod24.html#DogacDKOONEHAKKM95 http://www.acm.org/sigmod/record/issues/9509/dogac.ps