Vintage Paperback Book, "The Wizard of Starship Poseidon", Kenneth Bulmer, "Let the Spacemen Beware", Poul Anderson, 1963, paerback original (PBO), cover art by Gaughan. Ace Double #F-209. Grades GD. Some cover wear, some corner and edge wear, some spine wear, major crease, pages lightly browning, inside covers beginning to brown. Great reader copy.