Back to the Stone Age
Edgar Rice Burroughs
Pellucidar (5)
Tarzan at the Earth's Core
Pellucidar (4)
Tanar of Pellucidar
Pellucidar (3)
Pellucidar
Pellucidar (2)
At the Earth's Core
Pellucidar (1)
At the Earth's Core/Pellucidar/T[..] of Pellucidar