IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, vol. E91-D, no. 5, page. 1477 - 1480, 2008-05
IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS, vol. E91D, no. 5, page. 1489 - 1491, 2008-05
JOURNAL OF UNIVERSAL COMPUTER SCIENCE, vol. 14, no. 3, page. 318 - 346, 2008-02
IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES, vol. E91A, no. 1, page. 119 - 126, 2008-01