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

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

If you thought Sudoku was difficult, wait until you try Killer Sudoku! The next step up from normal Sudoku, the Killer puzzles use the same grid as Sudoku and r

The puzzles in this collection of treacherously difficult puzzles will stretch even the most advanced Su Doku enthusiast. You will need to use all of your best

Killer Su Doku poses an even greater challenge than the Fiendish Su Doku puzzles.Here are 100 previously unpublished puzzles for hard-core Su Doku addicts.