New York Post Electrifying Su Doku: 150 Difficult Puzzles
The official utterly addictive number-placing puzzleElectrify your mind with these all new Difficult puzzles. These entertaining puzzles offer more than just hours of fun&#8212;Su Doku engages your brain, 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!