12 books
Improve Your IQ on the Loo
Five-Minute Brainteasers
Brain Aerobics Stopwatch Puzzles
Super IQ Tests
Sit & SolveĀ® Brain-Boosting IQ Tests
102 Cryptic Crosswords
USA Today Brain-Flexing IQ Tests
Brain Flexing IQ Tests
Classic IQ Tests
Stopwatch Puzzles
The Brainiac's Puzzle Book
Globe and Mail Cryptic Crosswords,