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A collection of 200 previously unpublished Fiendish Su Doku puzzles.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.