Encyclopedia Brown and the Case of the Mysterious Handprints
Donald J. Sobol
The ten-year-old detective continues his war on crime in Idaville through ten more cases, for which the reader is invited to guess the solution before it is revealed.

by Laura Lee Hope (1984)
A scarecrow who disappears and reappears at other locations and an odd-shaped key lead the Bobbsey twins into another mystery.
Donald J. Sobol
The ten-year-old detective continues his war on crime in Idaville through ten more cases, for which the reader is invited to guess the solution before it is revealed.
Ken Kirkwood & Ray Marshall
A reporter and a photographer accompany a famous ornithologist to Magic Island in search of a rare bird that is missing from his collection. Detachable characters follow clues around a pop-up game board representing the island.
Remus F. Caroselli
Drum determines to find the connection between the bully who makes his life miserable and the mysterious, mean-looking stranger who begins appearing around their small seaside town.
Felicia Law
As a mysterious schooner approaches their island, the castaway monkeys, fearing that it is looking for them, use different units of measurement to help them track the schooner's speed and direction so that they may hide more effectively, unaware that the mysterious monkeys who watch them have other plans.