Hard Sudoku Books for Adults 240 Sudoku Logic Puzzles for 240 DaysPaperback, 20 September 2017

Would you like to hone your problem-solving skills? Then go ahead and do Sudoku. Sudoku helps you to better decide which boxes to fill first because some are easier than the rest. You solve it by recognizing what's there and what's not there. Over time, solving Sudoku will help you to look ahead and see the bigger picture. Solve Sudoku today!