Extreme Sudoku: 100 Difficult Level 4 Puzzles (English Edition)
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.