SUDOKU500 4x50 Sudoku Puzzle Book: easy to very hard New
SUDOKU500-500 Sudoku For Tricky Number Puzzles: Vol.1 Beginner Now available!
SUDOKU500-500 Sudoku For Tricky Number Puzzles: Vol.2 Advanced
SUDOKU500-500 Sudoku For Tricky Number Puzzles: Vol.3 Hard
SUDOKU500-500 Sudoku For Tricky Number Puzzles: Vol.4 Extreme
SUDOKU500-500 Sudoku For Tricky Number Puzzles: Vol.5 Random easy to extreme