- Sudoku Variants Collection Volume 2: 3 Variant Types, 270 Easy to Hard Puzzles: Killer Sudoku, Even-Odd Sudoku & Chain Sudoku
- The Hard to Extreme Sudoku Puzzle Book: 120 Large-Print Puzzles Volume 2
- The Hard to Extreme Sudoku Puzzle Book: 120 Large-Print Puzzles Volume 4
- The Hard to Extreme Sudoku Puzzle Book: 120 Large-Print Puzzles Volume 3
- Sudoku Variants Collection Volume 1: 3 Variant Types, 270 Easy to Hard Puzzles: Killer Sudoku, Even-Odd Sudoku & Chain Sudoku