by Cristina Smith, Rick Smith
There are also some variations of sudoku puzzles that are explored, like diagonal sudoku, consecutive, jigsaw sudoku, killer sudoku, chain, skyscraper, and butterfly sudoku. Most of the puzzles in this book are the normal style of puzzle, but there is an extra credit section with some of the variations of sudoku puzzles
At the back of the book there is a section with hints to help you out if you get stuck, and then another section with the answers to check your work.
I love the way this book is designed!
Disclaimer: I received a copy of this book from the publisher in exchange for a free and honest review. All the opinions stated here are my own true thoughts, and are not influenced by anyone.