You don't need to be a mathematical genius to solve the treacherous
puzzles in this collection of Fiendishly difficult puzzles, it's simply
a question of logic. Since the first Su Doku puzzle appeared in The
Times in November 2004, this classic game of logic has become a
phenomenon, with over 5 million copies of the Times Su Doku series
sold worldwide. Perfect for the advanced solver in need of a constant
supply of ultra-difficult puzzles, and guaranteed to provide hours of
mind-stretching entertainment.