Information Processing Letters
Information Processing Letters > 2001 > 80 > 6 > 279-285
Information Processing Letters > 2001 > 80 > 6 > 295-298
Information Processing Letters > 2001 > 80 > 6 > 305-309
Information Processing Letters > 2001 > 80 > 6 > 287-293
Information Processing Letters > 2001 > 80 > 6 > 311-316