Specially compiled to provide the most deadly Su Doku challenge, this is the only volume for Su Doku enthusiasts who need a puzzle that really tests their mettl

Warning: Not suitable for amateur puzzlers! Prepare yourself for the toughest Su Doku challenge there is. These diabolically difficult Ultimate Killer Su Doku p

These diabolically difficult Ultimate Killer Su Doku puzzles will really put your brain power to the test as you "warm up" with the 150 Deadly Killer puzzles be

This is Su Doku multiplied: 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

Just when you thought it was safe to pick up a pencil Killer Su Doku is based on the original Su Doku grid, with the same rules and numbers—1 to 9—but with