Do you love to solve difficult Sudoku X 9x9 puzzles? Then you should solve the Sudoku X puzzles in this book. You get to solve extremely difficult Sudoku X puzzles. You do not need to wade through tons of easy Sudoku X puzzles before getting to the real brain teasers. Once you pick up this book, you won't be able to put it back down. You have been warned!Sudoku X 9x9 - Hard to Extreme is a collection of 276 puzzles: 108 hard Sudoku X 9x9 puzzles 108 extreme Sudoku X 9x9 puzzles 60 extra logic puzzles The goal of Sudoku X is to fill in the empty cells, one number in each, so that each column, row, region, and the two main diagonals contain each number exactly once.I guarantee that every logic puzzle in this Sudoku X book has been carefully checked to ensure that each puzzle has only 1 solution.None of the puzzles in this book will appear in any of the other English PuzzleBooks.net books.Sudoku X is also known as Diagonal Sudoku, Kokonotsu, Taikakusen Nanpure and Diagonal Line Number Place.