Sudoku: 400+ Sudoku Puzzles with Easy, Medium, Hard, and Very Hard Difficulty Levels

Sudoku: 400+ Sudoku Puzzles (Easy, Medium, Hard, Very Hard) (Sudoku Puzzle Book) (Volume 2)

Sudoku: 400+ Sudoku Puzzles (Easy, Medium, Hard, Very Hard) (Sudoku Puzzle Book) (Volume 1)

Funster Tons of Sudoku 1,000+ Easy to Hard Puzzles: A bargain bonanza for Sudoku lovers

The Must Have 2017 Sudoku Puzzle Book: 365 daily sudoku puzzle book for 2017 sudoku. Sudoku puzzles for every day of the year. 365 Sudoku Games - 5 levels of difficulty (easy to hard)

Sudoku Puzzle Book Volume 1: 200 Puzzles

The Must Have 2016 Sudoku Puzzle Book: 366 puzzle daily sudoku book for the leap year. A challenge for every day of the year. 366 Sudoku Games - 5 levels of difficulty (easy to hard)

Sudoku (Ultimate Spiral Puzzles)

The Big Book of Sudoku

Ultimate Mind Games: With Over 400 Puzzles (Puzzle Books)

mental_floss Sudoku: It's the Brain Candy You've Been Craving!