Information Processing Letters
Information Processing Letters > 2004 > 92 > 4 > 199-205
Information Processing Letters > 2008 > 108 > 1 > 33-37
Information Processing Letters > 2013 > 113 > 5-6 > 151-155
Information Processing Letters > 2004 > 92 > 4 > 199-205
Information Processing Letters > 2008 > 108 > 1 > 33-37
Information Processing Letters > 2013 > 113 > 5-6 > 151-155