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

Prepare yourself for the toughest Su Doku challenge there is. These diabolically difficult Ultimate Killer Su Doku puzzles will really put your brainpower to th

Challenge your brain with these enjoyable puzzles. Specially compiled to provide the most deadly Su Doku challenge, this is the only volume for Su Doku enthusia