The Big Book of Sudoku
Sudoku (Ultimate Spiral Puzzles)
Brain GamesĀ® Sudoku (Brain Games (Unnumbered))
mental_floss Sudoku: It's the Brain Candy You've Been Craving!
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 2: Medium to Hard
Sudoku Vol. 2 Puzzle Pad: Easy to Medium
Sudoku: 400+ Sudoku Puzzles (Easy, Medium, Hard, Very Hard) (Sudoku Puzzle Book) (Volume 1)
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: Easy to Medium