- Medium Sudoku Puzzles Volume 1: Medium Sudoku Puzzles For Intermediate Players
- Medium and Hard Sudoku Puzzles: 200 Medium and Hard Sudoku Puzzles
- Very Hard Sudoku Puzzle Book Volume 1: Very Hard Sudoku Puzzles for Advanced Players
- Sudoku Puzzles Very Hard Volume 2: Very Hard Sudoku Puzzles for Advanced Players
- Very Hard Sudoku Puzzle Book Volume 2: Very Hard Sudoku Puzzles For Advanced Players





























