Killer Sudoku 12x12 Large Print - Easy to Hard - Volume 17 - 276 Puzzles: Snels, Nick: 9781502779472: Amazon.com: Books
Evil Sudoku 12 x 12 Puzzle Book: 150 Difficult Puzzles for the Ultimate Logic Challenge: Books, ZigZag Puzzle: 9781086486223: Amazon.com: Books
Large Print Sudoku 12x12 - 100 Hard Puzzles: Vey Difficult Sudoku Variant - Different Style of Sudoku Puzzle Book for Adults (Large Print Sudoku Variants): Hammond, Oliver: 9798702417677: Amazon.com: Books
Hard Sudoku 12 X 12 Puzzles (12 X 12 Sudoku Puzzle Books For Adults): Woodyear, Andrew: 9781540585158: Amazon.com: Books