Books like The Tarzan Twins
More by Edgar Rice Burroughs
A Princess of Mars1912
Tarzan of the Apes1912
The warlord of Mars #31914
The Gods of Mars1918
Thuvia, Maid of Mars1916
The Chessmen of Mars1922
The Return of Tarzan1915
At the Earth's Core1914
Tarzan the Untamed (Book #7)1920
The land that time forgot1918
The Beasts of Tarzan (Classic Ace SF, F-203)1914
Swords of Mars1936