Are you bored with 'difficult' sudoku puzzles? Looking for an extra challenge? This book is exactly what you need. Inside is a collection of 100 extremely, extra, super hard sudoku level 4 puzzles. Rich has done his best to handcraft the most challenging, extremely hard sudoku puzzles for you. This is for truly elite sudoku solvers . Exercise your best strategies in sudoku battle. These are so hard you might just have to google "how to solve very difficult sudoku puzzles"! Features: One puzzle per page. Each page is large print so each grid is easy to see and there's plenty of space for you to work the puzzles. There is a solutions key in the back, but you won't need it, right? Great for you, the sudoku ninja , or to give as a gift for other sudoku savants in your life. Check out the other great puzzles crafted by Rich Goodwin on Amazon ! He offers all other sudoku levels from introductory easy to expert hard in his Power Player Games series.