Centaur Aisle (Xanth Book 4)
Source of Magic (Xanth Book 2)
Ogre, Ogre (Xanth Book 5)
Night Mare (Xanth Book 6)
Dragon on a Pedestal (Xanth Book 7)
Crewel Lye (Xanth Book 8)
Golem in the Gears (Xanth Book 9)
Vale of the Vole (Xanth Book 10)
Heaven Cent (Xanth Book 11)