A First Sudoku Book (Dover Kids Activity Books)

Black Belt Sudoku® (Martial Arts Puzzles Series)

Sharp Minds for Seniors: The Ultimate Puzzle Book for Retirees to Boost Memory, Increase Cognitive Abilities and Have Fun with Brain Games and Activities (The Perfect Gift)

The Million Word Crossword Dictionary, 2nd Edition

Cuckoo Sudoku: Sudoku Variants That Will Drive You Batty

Beyond Black Belt Sudoku: If you have to ask, it's too hard for you. (Martial Arts Puzzles Series)

Brain Games - Sudoku (Chalkboard #1): Exercise Your Mind in Minutes (Volume 1)

The Big Book of TV Guide Crosswords #2

1,000++ All HARD Sudoku Puzzles: Top Quality Paper, Best Puzzles, Free Bonus! (Sodoku Puzzle Books for Adults)

Funster Relaxing Puzzle Book for Adults - Large Print Easy Crosswords, Word Search, Sudoku, Word Scrambles, and Mazes!: The fun activity book for adults with a variety of brain games.