400 HARD SUDOKU PUZZLES: Help Keep Your Mind Healthy And Active While Enjoying Yourself

It's Known that Solving Puzzles is Good for your Mental Health. When you Enjoy Solving Puzzles as Part of your Ongoing Routine, you can Delay the Onset of Alzheimer's Disease, and other Forms of Dementia. This Book has a 400 Hard Sudoku Puzzles, which are quite Challenging and are a Worthwhile and Thorough Mental Workout. Setting aside some Time Everyday to spend working at Solving these Puzzles will be a Treat for Your Brain.