Amazon.com description: Product Description: Sudoku has become an addiction for millions—and that?s great, because mind games help keep our brains in good working order. But even though the rules are simple, many solvers need some help when cracking the more complicated grids. That support is here in abundance…enough to take to you into the realm of the Very Difficult and even the Fiendish. Using this attractive guide, solvers will smoothly progress through 52 stages, each with a self-testing and timed puzzle to monitor progress. Chock-full of tactics and tips, and drawing on strategies evolved by Sudoku experts from Japan, Europe, and the United States, this little book takes you to the top.