Kin Sunada

• 30 Day Challenge Easy Logic Puzzle Book for Teens and Adults : Brain Teaser Games for Teenagers to Keep Your Brain Young
• 30 Day Challenge Hard Variety Puzzle Book for Adults : Mixed Logic Math Brain Teaser Games to Keep Your Brain Young
• 30 Day Challenge Mixed Logic Puzzle Book for Adults : Variety Math Brain Teaser Games to Keep Your Brain Young
• Challenge Yourself and Break Your Own Record - Easy Kakuro Cross Sums Puzzle Book for Adults with Time Log to Save Your Puzzle Playtime
• Challenge Yourself and Break Your Own Record - Easy&Hard Kakuro Cross Sums Puzzle Book for Adults with Time Log to Save Your Puzzle Playtime