Information Processing Letters
Information Processing Letters > 1995 > 53 > 1 > 49-54
Information Processing Letters > 1995 > 55 > 3 > 167-170
Information Processing Letters > 1995 > 55 > 5 > 247-250
Information Processing Letters > 1995 > 56 > 3 > 131-133
Information Processing Letters > 1996 > 57 > 1 > 49-52
Information Processing Letters > 1997 > 62 > 4 > 189-192
Information Processing Letters > 1997 > 62 > 5 > 251-254