Information Processing Letters
Information Processing Letters > 1995 > 54 > 2 > 101-103
Information Processing Letters > 2008 > 105 > 6 > 218-223
Information Processing Letters > 2008 > 108 > 5 > 320-325
Information Processing Letters > 2010 > 110 > 18-19 > 795-798
Information Processing Letters > 2010 > 110 > 22 > 1021-1025