High Wizardry

Third of the Young Wizards series
High Wizardry first edition hardcover (by Neal McPheeters)
High Wizardry Harcourt (first mass market paperback cover)
High Wizardry Corgi (UK) mass market paperback cover
High Wizardry Harcourt mmpb cover (by Cliff Nielsen)
High Wizardry Harcourt digest format cover (by Greg Swearingen)