504 Sudoku Puzzles Medium - Hard: Difficulty Medium - Hard Sudoku Puzzle Books for Adults Including Instructions and Answer Keys

Sudoku Puzzle Book, 600 Puzzles, 300 MEDIUM and 300 HARD: Improve Your Game With This Two Level Book (Sudoku Puzzle Books Champion Series)

512 SUDOKU Puzzles: Easy, Medium, Hard and Extreme Sudoku Puzzle Book including Instructions and answer keys

Sudoku Medium 500 Puzzles: Sudoku Puzzle Book - 500 Puzzles and Solutions - Medium Level - Volume 2. Tons of Fun for your Brain!

Sudoku: Medium - Hard: 200 advanced sudoku puzzles

Funster 500+ Sudoku Puzzles: Easy, Medium, Hard Sudoku Puzzle Book

Big Book of Sudoku: Huge Bargain Collection of 1000 Puzzles and Solutions, Easy to Expert Level, Challenge and Fun for your Brain!

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

500+ Hard Sudoku Puzzles for Adults: Sudoku Puzzle Books Hard (with answers)

Big Book of Sudoku

Sudoku Puzzle Book, 600 Puzzles, 300 MEDIUM and 300 HARD: Improve Your Game With This Two Level Book (Sudoku Puzzle Books Champion Series)

512 SUDOKU Puzzles: Easy, Medium, Hard and Extreme Sudoku Puzzle Book including Instructions and answer keys

Sudoku Medium 500 Puzzles: Sudoku Puzzle Book - 500 Puzzles and Solutions - Medium Level - Volume 2. Tons of Fun for your Brain!

Sudoku: Medium - Hard: 200 advanced sudoku puzzles

Funster 500+ Sudoku Puzzles: Easy, Medium, Hard Sudoku Puzzle Book

Big Book of Sudoku: Huge Bargain Collection of 1000 Puzzles and Solutions, Easy to Expert Level, Challenge and Fun for your Brain!

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

500+ Hard Sudoku Puzzles for Adults: Sudoku Puzzle Books Hard (with answers)

Big Book of Sudoku