At the Earth's Core
Edgar Rice Burroughs
Pellucidar (1)
Back to the Stone Age
Pellucidar (5)
Land of Terror
Pellucidar (6)
Pellucidar
Pellucidar (2)
Savage Pellucidar
Pellucidar (7)
Tanar of Pellucidar
Pellucidar (3)