136 books • 8 series
Book #1: Samurai Sudoku 100 Puzzles
Book #1: Sudoku Puzzle Book For Advanced Players
Book #4: Sudoku
Book #2: Sudoku Puzzle Book, 400 Puzzles, 200 Medium and 200 Hard
Book #3: Sudoku Puzzle Book, 400 Puzzles, 200 Hard and 200 Extra Hard
Book #5: Sudoku Puzzle Book, 500 MEDIUM Puzzles
Book #7: Sudoku Puzzle Book, 500 EXTRA HARD Puzzles
Book #9: Sudoku Puzzle Book, 1,000 Puzzles, 500 MEDIUM and 500 HARD
Book #22: Sudoku Puzzle Book, 600 Puzzles, 300 MEDIUM and 300 HARD
Book #37: Sudoku Puzzle Book, 1,000 Puzzles, 500 MEDIUM and 500 HARD
Book #40: Sudoku Puzzle Book, 1,500 Easy Puzzles
Book #42: Sudoku Puzzle Book, 1,500 HARD Puzzles
Book #43: Sudoku Puzzle Book, 1,500 EXTRA HARD Puzzles
Book #49: Sudoku Puzzle Book 400 Giant Size MEDIUM Puzzles
Book #50: Sudoku Puzzle Book 400 Giant Size HARD Puzzles
Book #11: Sudoku Puzzle Book, 400 Puzzles, 200 HARD and 200 Extra EXTRA HARD
Book #30: Sudoku Puzzle Book, 800 Extra Hard Puzzles
Book #1: SUDOKU TO GO (400 Puzzles, easy)