Calcudoku 9x9 Puzzles: Hard Puzzles for Adults

Are you an avid puzzler? This book will have your brain working hard to solve the problems it provides, but also gives the solutions to them at the back, just in case you encounter one that is particularly difficult to solve. It's the perfect antidote for rainy days, boring evenings when there's nothing on TV, or for those long commutes to and from work, where you just want to think about something else.