Information Processing Letters
Information Processing Letters > 2007 > 101 > 4 > 163-167
Information Processing Letters > 2007 > 101 > 4 > 141-147
Information Processing Letters > 2007 > 101 > 4 > 168-173
Information Processing Letters > 2007 > 101 > 4 > 148-155
Information Processing Letters > 2007 > 101 > 4 > 139-140
Information Processing Letters > 2007 > 101 > 4 > 174-179