- 400 amusing sudoku 9x9 classic puzzles + bonus in 250 labyrinths 21 x 21 very difficult levels (bonus puzzles need to be downloaded and printed)The way to mastery of Sudoku! The puzzles will lead you from the light level to the super heavy.- 400 unique Sudoku puzzles- 4 difficulty levels (all difficulty levels)- fitness for your brain- Original Sudoku for the power of your brain- just tested puzzles- answers at the end of the book- all riddles have only one proven solution - good mind support in excellent form - develops memory, logical thinking, helps to focus - creative possibilities expand. Ideal gift for all fans of puzzles. A great book for free time and studying the mind. I hope you enjoy the book. I would really appreciate it if you write a review.Best regards,Basford Holmes