Original Sudoku Page-A-Day® Calendar 2026: 365 Puzzles from the Editors at Nikoli

What If?: Serious Scientific Answers to Absurd Hypothetical Questions

1000+ Sudoku Puzzles for Adults: A Book With More Than 1000 Sudoku Puzzles from Easy to Hard for adults.

Math Riddles For Smart Kids: Math Riddles And Brain Teasers That Kids And Families Will love (Thinking Books for Kids)

Sudoku Book for Adults and Seniors with 3 Levels of Difficulty: 402 Puzzles & Solutions, Easy to Hard (The Perfect Gift for Puzzle Lovers) (Gifts for Men & Women)

The Ultimate Activity Book for Awesome Engineers: Tricky Brain Teasers, Mind Games and Logic Puzzle Book for Smart Adults (Perfect Gift for Engineers)

Brain Teasers for Smart Engineers: Tricky Brain Twisters, Mind Games and Fun Problem Solving for Engineers (Perfect Gifts for Engineers)

The Moscow Puzzles: 359 Mathematical Recreations (Dover Math Games & Puzzles)

My First Logic Workbook for Gritty Kids: Spatial Reasoning, Math Puzzles, Logic Problems, Focus Activities. (Develop Problem Solving, Critical Thinking, Analytical & STEM Skills in Kids Ages 4, 5, 6.)

The 125 Best Brain Teasers of All Time: A Mind-Blowing Challenge of Math, Logic, and Wordplay