New York Post Barracuda Su Doku: 150 Difficult Puzzles (New York Post Su Doku (Harper))
Here are all new Difficult puzzles . . . with teeth! More than just hours of entertainment, Su Doku engages your mind, improves your concentration, and helps you stay mentally fit. With 150 brand-new puzzles to complete, you’ll become a Su Doku master in no time!