The official utterly addictive number-placing puzzleGive your brain a workout with these all newDifficult-level puzzles. Their addictive power willnot only entertain--Su Doku puzzles engageyour mind, improve your concentration, and helpyou stay mentally fit. There's no excuse for slowthinking and flabby wits when you can trainyour brain!Beware of pale imitations. These are the original andofficial Su Doku puzzles by Wayne Gould--New York Post'sSu Doku puzzle master and one of Time magazine'sMost Influential People.