Earth Factor X By A. E Van Vogt Books / Paperback Books ISBN: 0879972491 / Publisher: Daw Books, August 1976 Price Starting at $71.58 Free Shipping Send to a friend Add to Wishlist Below is a list of products arranged by condition. Select the quantity of the product you desire and click the "Add" button. Used - Very Good Very Good condition. (Science Fiction) A copy that may have a few cosmetic defects. May also contain light spine creasing or a few markings such as an owner’s name, short gifter’s inscription or light stamp. $71.58 1 in Stock at Warehouse Quantity Add Free Shipping to continental U.S. OR $1.00 per item discount if shipped to store. Reviews Goodreads reviews for Earth Factor X