Positive brain, cool game. Suitable for adults and children. 6 puzzles per page. 500 Sudoku puzzles 6x6 medium levels. 502 Sudoku puzzles 6x6 hard levels. Thick paper. Glossy cover. Sudoku puzzles of medium and hard levels have a lot of names: sudoku, sudoku puzzles, sudoku game, sudoku solver, sudoku medium, sudoku hard, daily sudoku, play sudoku, game sudoku, medium sudoku puzzles, hard sudoku puzzles, le puzzle, sudoku with answers, sudoku grid, how to play sudoku, sudoku answers, play sudoku medium, play sudoku hard, sudoku puzzle solver, play sudoku game, simple sudoku, times sudoku, daily sudoku puzzle, mini sudoku, sudoku classic, sudoku puzzle game, su do ko, sudoku so, sudoku 9, sudoku or sudoku, b sudoku, medium sudoko, hard sudoko, game play sudoku, a sudoku, sudoku b, sudoku en linea, do sudoku, sudoku ku, sudoku g, sudoku s 2, number of sudoku puzzles, sudokop, sudoku d, puzzle, sudoku for kids, block puzzle, sudoku for dummies, jigsaw puzzles for sale, custom puzzles, puzzles for adults, puzzle books, jigsaw puzzle store, puzzles for kids, jigsaw puzzles for kids, childrens puzzles, puzzle ball, sudoku books, jigsaw puzzle maker, sudoku for children, brain teaser puzzles, sudoku board game. I hope you enjoy these puzzles. Best regards, Basford Holmes