We Know You Like It Hard . The Sudoku Lovers Only Book of Hard Puzzles 12+

📘 Be warned - inside this book are hard Sudoku puzzles reserved for the experts. It is not recommended that you try to solve these puzzles when you're just beginning to get into Sudoku. If you do, you might end up getting frustrated and with a low self-confidence. Work your way up by starting with the easy puzzles. Good luck!