TWIN PLANETS. New York: Paperback Library, Inc., . Small octavo, pictorial wrappers. First edition. Paperback Library 52-392. Bio-genetic superhuman twins must each rescue his own world -- Earth and Firma, mirror versions of each other in separate universes -- in order to save the other. Reginald 07195. A bright, good copy with some creasing to back cover and bumping of corners of last few leaves, else a bright, very good copy. (#143791).
"First Printing: January, 1967" on copyright page.