The Times Samurai Su Doku 15 : 100 Extreme Puzzles for the Fearless Su Doku Warrior (by The Times Mind Games)

Series: The Times Su Doku

Challenge yourself with number puzzles from The Times

For anyone who loves the challenge of Su Doku but manages to solve them within minutes, you can now enjoy the extended mental workout and ultimate endurance test of a five grid interlinked system.