Suguru, Rajesh Sudoku Hard 290+: Extreme Brain-Boosting Puzzles for Logic Lovers: Challenge Yourself with 290+ Tough Sudoku Puzzles Large Print Perfect for Experts & Puzzle Enthusiasts!

Studio, Raikō 1000+ Sudoku Puzzles for Adults: Easy to Very Hard: Brain-Boosting Logic Challenges with Full Solutions

Kumari, Nidhi Sudoku Challenge Book for Adults 300 Brain-Boosting Puzzles: Improve Focus, Memory & Logic Easy to Hard Levels Perfect Brain Exercise for Adults & Seniors

Reang, Mr Dilip Kumar The Ultimate Brain Puzzle Book for Adults & Teens: Challenge Your Mind with Word Searches, Sudoku, Crosswords, and Logic Games Fun, Relaxing & Brain-Boosting Puzzles for All Skill Levels

Mubasher, Khaula The Ultimate Activity Book for Smart Boys: 100+ Mazes, Word Searches, Crosswords, Sudoku, Dot to Dot, Logic Puzzles, and More Brain-Boosting Challenges (Kids Activity Books)

Mubasher, Khaula The Ultimate Activity Book for Smart Girls: 100+ Mazes, Word Searches, Crosswords, Sudoku, Dot to Dot, Logic Puzzles, and More Brain-Boosting Challenges (Kids Activity Books)

Suguru, Rajesh Multi Difficulty Sudokus: Total 400+ Brain-Boosting Puzzles and Solutions 4 difficulty levels Very Easy, Easy, Normal, and Hard