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