11 books • 3 series
The Christmas Stocking Book of Brainteasers (Puffin jokes, games, puzzles)
A Diversity of Puzzles
Brain Puzzler's Delight (Right Before Your Eyes S.)
Penguin Book of Brain Teasers
101 Brain Puzzlers
The Island of Imperfection Puzzle Book
Island of Imperfection
Great Detective Puzzle Book
The Puffin Book of Brainteasers
Learning to Think
Learning to Philosophize (Pelican S.)