If Classic Sudoku cannot satisfy you anymore, try the X-Sudoku Level Easy.You have the new challenge for diagonal!In the Expert level, you have 27-28 known numbers.Good luck! X-Sudoku Easy level vol.1 Details - Small Print (5x8) to easily take with - 100 Easy Level Sudoku Puzzles Collection- You can challenge yourself by writing down the time, you used. -Each puzzle has 1,2,3,4,5,6,7,8,9 on the top. It is for you when you clear one number, Bang it offThese series have four different levels: easy, normal, hard, and expert. This book is an easy level. if you need other levels, please check "Mike Murphy Sudoku". Enjoy!