27 books • 2 series
Sudoku Puzzle Master Book 1,200 Puzzles, 300 Easy, 300 Medium, 300 Hard and 300 Extra Hard
Sudoku Puzzle Book 1,000 Extra Hard Puzzles, Jumbo Bargain Size Book (Sudoku Puzzle Book Master, #21)
Sudoku Puzzle Book 1,000 Easy Puzzles, Jumbo Bargain Size Book (Sudoku Puzzle Book Master, #18)
Sudoku Puzzle Book 800 Puzzles, 400 Hard and 400 Extra Hard (Sudoku Puzzle Book Master, #17)
Sudoku Puzzle Book 800 Puzzles, 400 Medium and 400 Hard (Sudoku Puzzle Book Master, #16)
Sudoku Puzzle Book 600 Puzzles, 300 Medium and 300 Hard (Sudoku Puzzle Book Master, #10)
Sudoku Puzzle Book 600 Puzzles, 300 Easy and 300 Medium (Sudoku Puzzle Book Master, #9)