Space (February 1972) 79975 SF E. C. Tubb Technos / E. C. Tubb A Scatter of Stardust (March 1972) 16640 SF Jack Vance The Dragon Masters / 5 Gold Bands (April 1972) 00990 SF Susan K. Putney Against Arcturus / Dean R. Koontz Time Thieves (May 1972) 37062 SF A. Bertram Chandler The Inheritors / The Gateway to Never (June 1972) 10293 SF John T. Phillifent (as John Rackham) Earthstrings / Ken Bulmer The Chariots of Ra (July 1972) 06612 SF Mack Reynolds Blackman's Burden / Border, Breed Nor Birth (August 1972) 15697 SF Philip K. Dick The Unteleported Man / Dr. Futurity (September 1972) 31755 SF A. Bertram Chandler The Hard Way Up / Robert Lory The Veiled World (October 1972) 11451 SF A. Bertram Chandler Coils of Time / Into The Alternate Universe (November 1972) 22576 SF Marion Zimmer Bradley Falcons of Narabedla / The Dark Intruder & Other Stories (December 1972) 76960 SF Lester del Rey Badge of Infamy / The Sky is Falling (January 1973) 11650 SF Mack Reynolds Computer War / Code Duello (February 1973) 93900 SF Ross Rocklynne The Sun Destroyers / Edmond Hamilton A Yank at Valhalla (March 1973) 16641 SF Jack Vance The Dragon Masters / The Last Castle (April 1973) 53415 SF John T. Phillifent Hierarchies / Doris Piserchia Mister Justice (May 1973) 76380 SF William F. Temple Battle on Venus / William F. Temple The Three Suns of Amara (June 1973) 89301 SF E. C. Tubb Derai / The Winds of Gath (July 1973) 48245 SF John T. Phillifent Life With Lancelot / William Barton Hunting on Kunderer (August 1973) Serial number 48245, above, was the last Ace Double published in the tête-bêche format. The remainder of the books listed in this section contain two novels, but are published in the traditional way with a single cover and the text the same way up throughout the book. Another Ace SF double(G-723-Andre Norton-Star Hunter/Voodoo Planet) was published in 1968 as a traditional reprint in the second G series (begun in 1964). G-723 was the only traditionally printed SF double included in that series and thus does not fit under any of the categories listed here. 66995 SF Mack Reynolds The Rival Rigelians / Planetary Agent X (June 1974) 14250 SF Mack Reynolds Depression Or Bust / Dawnman Planet (September 1974) 20571 SF Samuel R. Delany The Ballad of Beta-2 / Empire