JOURNAL OF SYSTEMS AND SOFTWARE, vol. 78, no. 3, page. 257 - 269, 2005-12
COMPUTER SYSTEMS SCIENCE AND ENGINEERING, vol. 21, no. 6, page. 395 - 404, 2006-11
VLDB JOURNAL, vol. 16, no. 3, page. 371 - 387, 2007-07
IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING, vol. 18, no. 2, page. 245 - 260, 2006-02