A Journey to the Earth's Interior - by Marshall B. Gardner
Beasts, Men and Gods - by Ferdinand Ossendowski
Critical Mass - The Real Story of the Birth of the Atomic Bomb and the Nuclear Age - by Carter P. Hydrick
Etidorhpa - by John Uri Lloyd
Genesis for The New Space Age - Secret Development of The Round Wing Plane... - by John B. Leith
Mysteries of the Inner Earth - by David Pratt
Plate Tectonics - A Paradigm Under Threat - by David Pratt
Sunken Continents versus Continental Drift - by David Pratt
The Hollow Earth and The Underground Cities - Telos
The Hollow Earth - by Dr. R. W. Bernard
The Hollow Earth's Messages
The Phantom of the Poles - by William Reed
The Smokey God - by Willis George Emerson
The True Origin of The Flying Saucers - Greatest Geographical Discovery in History...- by Raymond Bernard
Vril - The Power of The Coming Race - by Sir Edward Bulwer-Lytton
Books & Treatises: Hollow Earth Theory (basecamp.com)
Beasts, Men and Gods - by Ferdinand Ossendowski
Critical Mass - The Real Story of the Birth of the Atomic Bomb and the Nuclear Age - by Carter P. Hydrick
Etidorhpa - by John Uri Lloyd
Genesis for The New Space Age - Secret Development of The Round Wing Plane... - by John B. Leith
Mysteries of the Inner Earth - by David Pratt
Plate Tectonics - A Paradigm Under Threat - by David Pratt
Sunken Continents versus Continental Drift - by David Pratt
The Hollow Earth and The Underground Cities - Telos
The Hollow Earth - by Dr. R. W. Bernard
The Hollow Earth's Messages
The Phantom of the Poles - by William Reed
The Smokey God - by Willis George Emerson
The True Origin of The Flying Saucers - Greatest Geographical Discovery in History...- by Raymond Bernard
Vril - The Power of The Coming Race - by Sir Edward Bulwer-Lytton
Books & Treatises: Hollow Earth Theory (basecamp.com)