Indiana Jones: Prequels
Shown by first publication year; this may not be reading order.
Indiana Jones and the Peril at Delphi
Indiana Jones and the Dance of the Giants
Indiana Jones and the Unicorn's Legacy
Indiana Jones and the Interior World
Indiana Jones and the Sky Pirates
Indiana Jones and the White Witch
Indiana Jones and the Philosopher's Stone
Indiana Jones and the Dinosaur Eggs
Indiana Jones and the Hollow Earth
Indiana Jones and the Secret of the Sphinx