Which two psychologists was Campbell synthesizing? Which elements of the hero's adventure correspond to the theories of these scholars?

Campbell studied how Sigmund Freud and Carl Jung used the idea of myth in psychology. Really, all the elements in the hero's journey utilize parts of both psychologists’ work. Everything from the call to adventure to the transformation borrows from Freudian and Jungian themes. I would say that Campbell relied more heavily on Jung.

Which two psychologists was Campbell synthesizing? Which elements of the hero's adventure correspond to the theories of these scholars?