Keith Kay

The giant book of optical puzzles

Colorful Puzzles for Wise Eyes

A Little Giant Book

Brainstrains

The Little Giant Book of Optical Tricks

Stories in the Bozeman Trail- the Untold Story of Red Cloud, an American Legend

Sustainable Recovery

Book of Optical Tricks (Little Giant Books)

Grand Livre Du Casse-Tete Optique

Fun with Optical Illusions (Mini Masters)