12 X Sudoku Challenges (Vol 2): Medium to Very Hard Logic Puzzles

12x12 Sudoku Challenges (Vol 1): Medium to Very Hard Logic Puzzles

12x12 Sudoku for Beginners (Vol 1): Very Easy to Medium Logic Puzzles

2 SUDOKU VERY HARD PUZZLES: Perfect logic puzzles for brain training.

150 Normal Sudoku Puzzles: Master the Next Stage of Logic with Engaging...