18 books • 5 series
Train Your Brain for Clarity
Train Your Brain: Mental Agility
The Train Your Brain Mind Exercise
Train Your Brain Mind Games
The Train Your Brain Challenge
Go Fun! Brainsnack Draw with Numbers, 11 (Go Fun!, #11)
Go!Games Mega Book of Sudoku (Go!Games)
The Train Your Brain Workout
Sudoku-Utopia
Brain Twisters, Mind Benders, and Puzzle Conundrums
Baffling Binary Puzzles
Brain Busting, Mind Twisting, IQ Crushing Puzzles
Brainsnack Visual Mind Teasers
Math Puzzles (New Sip & Solve)
Wild Animal Sudoku
Spaceship Sudoku (Sudoku (Sterling Publishing))
Farm Animal Sudoku (Sudoku (Sterling Publishing))
Brainstrains(r) Eye-Popping Puzzles (Brainstrains)