202 books • 15 series
Turn On The Logic Small Calcudoku - 200 Easy Puzzles 5x5 (Volume 1) (Small Calcudoku Puzzle Book, #1)
Turn On The Logic Small Calcudoku - 200 Normal Puzzles 5x5 (Volume 2) (Small Calcudoku Puzzle Book, #2)
Turn On The Logic Straights 200 Hard Puzzles 9x9 (Volume 10) (Straights Puzzle Book, #10)