- Hard Sudoku puzzle books vol. 1: Hard, Very Hard and Extremely Hard Sudoku - Total 300 Sudoku puzzles to solve - Includes solutions
- Hard Sudoku Puzzle Book For Adults: Challenging Sudoku puzzles, 60 Hard, 60 Very Hard And 60 Extremely Hard Sudoku Puzzles Inside. Two puzzles on a ...
- Very Difficult Sudoku Puzzles For Adults: Hard Sudoku Puzzle Book. 180 Sudoku puzzles from Hard To Extreme Difficulty. Solutions Included
- Very Easy Sudoku Puzzle Book For Beginners: 250 beginner level Sudoku puzzles. If you are new to Sudoku, you will also learn basics and simple Sudoku strategy in this book.
- Sudoku easy - Large print Sudoku Puzzles For Adults book 1: 220 Relaxing Large Print Sudoku Puzzles For Beginners. Two puzzles a page. Answers to puzzles Included.