Test your powers of logic with these challenging Su Doku puzzles.A collection of 200 previously unpublished Fiendish Su Doku puzzles. Perfect for the expert solver in need of a constant supply of ultra-difficult puzzles. Guaranteed to provide hours of absorbing, brain-stretching entertainment.Since the first Su Doku puzzle appeared in The Times in November 2004, they have become a phenomenon, with over 4 million copies of The Times Su Doku books sold worldwide. You don't need to be a mathematical genius to solve these puzzles; it is simply a question of logic. Each puzzle has a unique solution – and there's no guesswork required.The Times Su Doku remains the original, the best and the market leader. The puzzles are provided by Wayne Gould, the man who started it all.