Einstein's Riddle: Riddles, Paradoxes, and Conundrums to Stretch Your Mind
Challenging Logic Puzzles (Mensa®)
Sam Loyd's Cyclopedia of 5000 Puzzles tricks and Conundrums with Answers
The Colossal Book of Short Puzzles and Problems
The Moscow Puzzles: 359 Mathematical Recreations (Dover Recreational Math)
Are You Smart, or What? A Bizarre Book of Games & Fun for Everyone
Match Wits With Mensa: The Complete Quiz Book