When you buy this book you get an electronic version (PDF file) of the interior of this book. You can play the puzzles in this book on your mobile phone! Jigsaw Sudoku is Sudoku with a twist. Instead of square shaped regions, the regions are irregularly shaped. This makes solving a Jigsaw Sudoku puzzle that little bit more difficult than Sudoku. This book is ideal if you love to solve difficult Jigsaw Sudoku puzzle. You do not need to wade through tons of easy Jigsaw Sudoku puzzle 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! Only 1 large print puzzle per page, with lots of white space for scribbling. Jigsaw Sudoku 9x9 - Hard is a collection of 276 puzzle: 216 hard Jigsaw Sudoku 9x9 puzzle 60 extra logic puzzle I guarantee that every logic puzzle in this Jigsaw Sudoku puzzle book has been carefully checked to ensure that each puzzle has only 1 solution. None of the puzzle in this book will appear in any of the other English PuzzleBooks.net books. Jigsaw Sudoku is also known as Geometry Sudoku, Irregular Sudoku, Squiggly Sudoku, Kikagaku Nanpure.