The Times Samurai Su Doku Book 4

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

With its larger and more complex grid, Samurai is Su Doku multiplied. With a five grid interlinked system, every column, row, and 3x3 box must contain the digits 1 to 9. Where the puzzles overlap, the rows and columns do not go beyond their usual 9x9 length, but the interlocking boxes give you more clues—and more complexity. With an...