22 books
Slitherlink - 108 Puzzles; Medium, Hard and Very Hard; Volume 3; Large Print (Cactus Puzzles)
Slitherlink - 108 Puzzles; Medium, Hard and Very Hard; Volume 1; Large Print (Cactus Puzzles)
Slitherlink - 108 Puzzles; Medium, Hard and Very Hard; Volume 2; Large Print (Cactus Puzzles)