Are you ready for some of the toughest Sudoku puzzles? Don't believe it? Check the puzzle on the back cover and see if you can solve it.Large print puzzles with two on each page. Easy to read if not easy to solve.Big 11 x 8.5-inch book (A4 size). Lots of room to note candidates.Large 30pt Century Gothic easy to read font.300 puzzles to keep you busy. Solutions are included at the back in case they are too hard for you to solve.The puzzles are for those that find hard sudoku too easy. Use the sample on the back cover to judge if the level is right for you.