List of Ace SF letter-series single titles

Ace Books have published hundreds of science fiction titles, starting in 1953. Many of these were Ace Doubles (dos-a-dos format), but they also published many single volumes. Between 1953 and 1968, the books had a letter-series identifier; after that date they were given five digit numeric serial numbers. There were a total of 374 letter-series sf titles.

The list given here gives a date of publication; in all cases this refers to the date of publication by Ace, and not the date of original publication of the novels. For more information about the history of these titles, see Ace Books, which includes a discussion of the serial numbering conventions used and an explanation of the letter-code system.

D and S Series

*S-066 "SF" L. Ron Hubbard "Return to Tomorrow"
*S-090 "SF" Robert Moore Williams "The Chaos Fighters"
*D-096 "SF" Andre Norton "The Last Planet" (Special Edition-half of the Ace Double with same code-circa 1959)
*D-110 "SF" Isaac Asimov "The 1,000 Year Plan" (Special Edition-half of the Ace Double with same code-circa 1959)
*D-121 "SF" Andre Norton "The Stars Are Ours!" (Special Edition-half of the Ace Double with same code-circa 1959)
*D-125 "SF" Isaac Asimov "The Man Who Upset the Universe" (1955)
*S-133 "SF" Donald A. Wollheim (Ed.) "Adventures On Other Planets"
*D-146 "SF" Murray Leinster "The Forgotten Planet" (Special Edition-half of the Ace Double with same code-circa 1959)
*D-155 "SF" Jules Verne "A Journey To The Center Of The Earth" (1956)
*D-169 "SF" Jack Williamson And James E. Gunn "Star Bridge"
*S-183 "SF" Donald A. Wollheim (Ed.) "The End of the World"
*D-187 "SF" A. E. van Vogt "The Pawns of Null-A"
*D-211 "SF" Philip K. Dick "Eye in the Sky" (1957)
*D-233 "SF" Rex Gordon "First on Mars"
*D-245 "SF" Jules Verne "Off on a Comet" (1957)
*D-261 "SF" Philip K. Dick "The Variable Man And Other Stories" (1957)
*D-274 "SF" Charles Eric Maine "World Without Men" (1958)
*D-283 "SF" Clifford D. Simak "City" (1958)
*D-309 "SF" H. G. Wells "The Island Of Dr. Moreau" (1958)
*D-324 "SF" Ray Cummings "Brigands of the Moon" (1958)
*D-327 "SF" Jeff Sutton "First on the Moon"
*D-339 "SF" Clifford D. Simak "Ring Around the Sun’’
*D-340 "SF" Philip K. Dick "Solar Lottery" (1959)
*D-350 "SF" Peter George (as Peter Bryant) "Red Alert"
*D-354 "SF" Donald A. Wollheim (ed.) "The Hidden Planet: Science-Fiction Adventures On Venus" (1959)
*D-366 "SF" Alan E. Nourse and J. A. Meyer "The Invaders Are Coming"
*D-377 "SF" Jeff Sutton "Bombs in Orbit" (1959)
*D-388 "SF" H. G. Wells "When the Sleeper Wakes" (1959)
*D-397 "SF" Jules Verne "Journey to the Center of the Earth"
*D-405 "SF" Rex Gordon "First to the Stars"
*D-422 "SF" Anthony Boucher and J. Francis Mccomas (eds.) "The Best From F & SF, 3rd Series"
*D-455 "SF" Anthony Boucher (Ed.) "The Best From Fantasy And Science Fiction, 4th Series" (1960)
*D-461 "SF" Andre Norton "The Time Traders" (1960)
*D-468 "SF" Eric Frank Russell "Sentinel of Space" (1960)
*D-473 "SF" Eric Temple Bell (As John Taine) "The Greatest Adventure’’
*D-478 "SF" Jeff Sutton "Spacehive" (1960)
*D-482 "SF" A. E. van Vogt "The Weapon Shops of Isher" (1961)
*D-490 "SF" Donald A. Wollheim (Ed.) "Adventures on Other Planets" (1961)
*D-498 "SF" Andre Norton "Galactic Derelict" (1961)
*D-504 "SF" Jules Verne "Master of the World" (1961)
*D-516 "SF" Otis Adelbert Kline "The Swordsman Of Mars" (1961)
*D-525 "SF" Murray Leinster "This World Is Taboo" (1961)
*D-527 "SF" Andre Norton "Star Guard" (1961)
*D-528 "SF" Murray Leinster "The Forgotten Planet"
*D-530 "SF" Robert Moore Williams "The Day They H-Bombed Los Angeles" (1961)
*D-531 "SF" Otis Adelbert Kline "The Outlaws of Mars"
*D-534 "SF" Andre Norton "Daybreak - 2250 A. D. " (1961)
*D-535 "SF" Ray Cummings "The Shadow Girl" (1962)
*D-537 "SF" H. G. Wells "The Island of Dr. Moreau" (1961)
*D-538 "SF" Isaac Asimov "The 1,000 Year Plan" (1961)
*D-541 "SF" Alan E. Nourse "Scavengers in Space" (1962)
*D-542 "SF" Andre Norton "The Last Planet" (1962)
*D-544 "SF" Frank Belknap Long "Space Station #1" (1962)
*D-546 "SF" Andre Norton "The Crossroads of Time"
*D-547 "SF" John Brunner "The Super Barbarians" (1962)
*D-550 "SF" Poul Anderson "No World of Their Own" (1962)
*D-551 "SF" Peter George (as Peter Bryant) "Red Alert"
*D-555 "SF" Jack Williamson "The Trial of Terra" (1962)
*D-568 "SF" Poul Anderson "Star Ways" (1962)

F Series

*F-105 "SF" Anthony Boucher (ed.) "The Best From Fantasy And Science Fiction, Fifth Series"
*F-109 "SF" Andre Norton "Storm Over Warlock" (1961)
*F-114 "SF" Wallace West "The Bird of Time" (1961)
*F-123 "SF" Leigh Brackett "The Nemesis From Terra"
*F-131 "SF" Anthony Boucher (ed.) "The Best From Fantasy And Science Fiction, Sixth Series"
*F-135 "SF" Leigh Brackett "The Long Tomorrow" (1962)
*F-154 "SF" A. E. van Vogt "The Wizard of Linn" (1962)
*F-156 "SF" Edgar Rice Burroughs "At The Earth's Core" (1962)
*F-157 "SF" Edgar Rice Burroughs "The Moon Maid" (1962)
*F-158 "SF" Edgar Rice Burroughs "Pellucidar" (1962)
*F-159 "SF" Edgar Rice Burroughs "The Moon Men" (1962)
*F-162 "SF" Anthony Boucher (ed.) "The Best From Fantasy And Science Fiction, Seventh Series" (1962)
*F-167 "SF" Andre Norton "Catseye" (1962)
*F-168 "SF" Edgar Rice Burroughs "Thuvia, Maid of Mars" (1962)
*F-169 "SF" Edgar Rice Burroughs "Tarzan and the Lost Empire" (1962)
*F-170 "SF" Edgar Rice Burroughs "The Chessmen of Mars" (1962)
*F-171 "SF" Edgar Rice Burroughs "Tanar Of Pellucidar" (1962)
*F-174 "SF" Rex Gordon "First Through Time" (1962)
*F-178 "SF" Donald A. Wollheim (ed.) "More Adventures On Other Planets" (1963)
*F-179 "SF" Edgar Rice Burroughs "Pirates of Venus" (1963)
*F-180 "SF" Edgar Rice Burroughs "Tarzan at the Earth's Core" (1963)
*F-181 "SF" Edgar Rice Burroughs "The Master Mind of Mars" (1963)
*F-182 "SF" Edgar Rice Burroughs "The Monster Men" (1963)
*F-183 "SF" Andre Norton "The Defiant Agents" (1963)
*F-188 "SF" Philip Francis Nowlan "Armageddon 2419 A.D." (1962)
*F-189 "SF" Edgar Rice Burroughs "Tarzan the Invincible" (1963)
*F-190 "SF" Edgar Rice Burroughs "A Fighting Man of Mars" (1963)
*F-191 "SF" Jules Verne "Journey to the Center of the Earth" (1963)
*F-192 "SF" Andre Norton "Star Born" (1963)
*F-193 "SF" Edgar Rice Burroughs "The Son of Tarzan" (1963)
*F-194 "SF" Edgar Rice Burroughs "Tarzan Triumphant" (1963)
*F-197 "SF" Andre Norton "Witch World" (1963)
*F-201 "SF" Paul MacTyre "Doomsday, 1999" (1963)
*F-203 "SF" Edgar Rice Burroughs "The Beasts of Tarzan"
*F-204 "SF" Edgar Rice Burroughs "Tarzan and the Jewels of Opar" (1963)
*F-205 "SF" Edgar Rice Burroughs "Tarzan and the City of Gold" (1963)
*F-206 "SF" Edgar Rice Burroughs "Jungle Tales of Tarzan" (1963)
*F-207 "SF" Andre Norton "The Stars Are Ours! "
*F-210 "SF" Peter George (as Peter Bryant) "Red Alert"
*F-211 "SF" Otis Adelbert Kline "Planet of Peril" (1963)
*F-212 "SF" Edgar Rice Burroughs "Tarzan and the Lion Man"
*F-213 "SF" Edgar Rice Burroughs "The Land That Time Forgot" (1963)
*F-216 "SF" Isaac Asimov "The Man Who Upset the Universe" (1963)
*F-217 "SF" Anthony Boucher (ed.) "The Best From Fantasy And Science Fiction, Eighth Series" (1963)
*F-220 "SF" Edgar Rice Burroughs "The People That Time Forgot" (1963)
*F-221 "SF" Edgar Rice Burroughs "Lost on Venus" (1963)
*F-222 "SF" Jeff Sutton "First on the Moon" (1963)
*F-225 "SF" H. Beam Piper "Space Viking" (1963)
*F-226 "SF" Andre Norton "Huon of the Horn" (1963)
*F-231 "SF" Andre Norton "Star Gate" (1963)
*F-232 "SF" Edgar Rice Burroughs "The Land of Hidden Men" (1963)
*F-233 "SF" Edgar Rice Burroughs "Out of Time's Abyss" (1963)
*F-234 "SF" Edgar Rice Burroughs "The Eternal Savage" (1963)
*F-235 "SF" Edgar Rice Burroughs "The Lost Continent" (1963)
*F-236 "SF" Andre Norton "The Time Traders"
*F-239 "SF" Clifford D. Simak "Time And Again" (1963)
*F-240 "SF" H. G. Wells "When the Sleeper Wakes" (1963)
*F-241 "SF" Jack Williamson and James E. Gunn "Star Bridge" (1963)
*F-243 "SF" Andre Norton "Lord Of Thunder" (1963)
*F-245 "SF" Edgar Rice Burroughs "Back to the Stone Age" (1963)
*F-246 "SF" Thea von Harbou "Metropolis" (1963)
*F-247 "SF" Edgar Rice Burroughs "Carson of Venus" (1963)
*F-248 "SF" Ray Cummings "Beyond the Stars" (1963)
*F-251 "SF" Philip K. Dick "The Game-Players of Titan" (1963)
*F-255 "SF" Philip E. High "The Prodigal Sun" (1964)
*F-256 "SF" Edgar Rice Burroughs "Land Of Terror" (1964)
*F-257 "SF" Fletcher Pratt "Alien Planet" (1964)
*F-258 "SF" Edgar Rice Burroughs "The Cave Girl" (1964)
*F-259 "SF" Otis Adelbert Kline "Prince Of Peril" (1964)
*F-263 "SF" Andre Norton "Web Of The Witch World" (1964)
*F-267 "SF" Robert P. Mills (ed.) "The Best From Fantasy And Science Fiction, 9th Series" (1964)
*F-268 "SF" Edgar Rice Burroughs "Escape on Venus" (1964)
*F-269 "SF" J. H. Rosny "Quest of the Dawn Man" (1964)
*F-270 "SF" Edgar Rice Burroughs "The Mad King" (1964)
*F-271 "SF" Edmond Hamilton "Outside the Universe" (1964)
*F-274 "SF" H. Beam Piper "The Cosmic Computer" (1964)
*F-277 "SF" John Brunner "To Conquer Chaos" (1964)
*F-279 "SF" Andre Norton (as Andrew North) "Sargasso of Space"
*F-280 "SF" Edgar Rice Burroughs "Savage Pellucidar" (1964)
*F-281 "SF" Pierre Benoit "Atlantida" (1964)
*F-282 "SF" Edgar Rice Burroughs "Beyond The Farthest Star" (1964)
*F-283 "SF" Sax Rohmer "The Day the World Ended" (1964)
*F-287 "SF" Andre Norton "The Key Out of Time" (1964)
*F-291 "SF" Andre Norton "Plague Ship" (1964)
*F-293 "SF" E. C. Tubb "Moonbase" (1964)
*F-294 "SF" Otis Adelbert Kline "The Port of Peril" (1964)
*F-295 "SF" A. E. van Vogt "The World of Null-A"
*F-296 "SF" Edwin L. Arnold "Gulliver of Mars" (1964)
*F-297 "SF" Henry Kuttner "The Valley of the Flame" (1964)
*F-301 "SF" Philip K. Dick "The Simulacra" (1964)
*F-303 "SF" Marion Zimmer Bradley "The Bloody Sun"
*F-304 "SF" Ralph Milne Farley "The Radio Beasts" (1964)
*F-305 "SF" Robert E. Howard "Almuric" (1964)
*F-306 "SF" C. L. Moore and Henry Kuttner "Earth's Last Citadel" (1964)
*F-307 "SF" Gardner F. Fox "Warrior Of Llarn" (1964)
*F-308 "SF" Andre Norton "Judgment On Janus" (1964)
*F-309 "SF" Philip K. Dick "Clans of the Alphane Moon" (1964)
*F-310 "SF" Andre Norton "Galactic Derelict" (1964)
*F-311 "SF" Donald A. Wollheim (ed.) "Swordsmen In The Sky" (1964)
*F-312 "SF" Ralph Milne Farley "The Radio Planet"
*F-313 "SF" Ray Cummings "A Brand New World" (1964)
*F-314 "SF" James H. Schmitz "The Universe Against Her" (1964)
*F-315 "SF" Andre Norton "The Beast Master"
*F-317 "SF" James White "The Escape Orbit" (1965)
*F-318 "SF" Austin Hall "The Spot Of Life" (1965)
*F-319 "SF" Edmond Hamilton "Crashing Suns" (1965)
*F-320 "SF" John Brunner (as Keith Woodcott) "The Martian Sphinx" (1965)
*F-321 "SF" Otis Adelbert Kline "Maza of the Moon" (1965)
*F-322 "SF" Samuel R. Delany "City of a Thousand Suns" (1965)
*F-323 "SF" Andre Norton "Daybreak - 2250 A.D. "
*F-325 "SF" Andre Norton "Ordeal in Otherwhere" (1965)
*F-326 "SF" Lin Carter "The Wizard of Lemuria" (1965)
*F-327 "SF" Henry Kuttner "The Dark World" (1965)
*F-328 "SF" Edward E. Smith "The Galaxy Primes" (1965)
*F-329 "SF" Andre Norton "Storm Over Warlock" (1965)
*F-330 "SF" Avram Davidson "What Strange Stars and Skies" (1965)
*F-332 "SF" Andre Norton "Three Against the Witch World" (1965)
*F-333 "SF" L. Sprague de Camp "Rogue Queen" (1965)
*F-334 "SF" Rex Dean Levie "The Insect Warriors" (1965)
*F-335 "SF" Robert Moore Williams "The Second Atlantis" (1965)
*F-337 "SF" Philip K. Dick "Dr. Bloodmoney, or How We Got Along After the Bomb" (1965)
*F-342 "SF" H. Beam Piper "Lord Kalvan of Otherwhen" (1965)
*F-343 "SF" Ray Cummings "The Exile of Time" (1965)
*F-344 "SF" Henry Kuttner "The Well of the Worlds" (1965)
*F-345 "SF" Homer Eon Flint "The Lord of Death and yhe Queen of Life" (1965)
*F-346 "SF" John W. Campbell, Jr. "The Black Star Passes" (1965)
*F-347 "SF" Ian Wright "The Last Hope of Earth" (1965)
*F-350 "SF" Marion Zimmer Bradley "Star Of Danger" (1965)
*F-353 "SF" Avram Davidson "Rogue Dragon" (1965)
*F-354 "SF" Gardner F. Fox "The Hunter Out Of Time" (1965)
*F-355 "SF" Homer Eon Flint "The Devolutionist and The Emancipatrix" (1965)
*F-356 "SF" Henry Kuttner "The Time Axis" (1965)
*F-357 "SF" Andre Norton "Year of the Unicorn" (1965)
*F-361 "SF" John Brunner "The Day of the Star Cities" (1965)
*F-363 "SF" Ray Cummings "Tama of the Light Country" (1965)
*F-364 "SF" John W. Campbell, Jr. "The Mightiest Machine" (1965)
*F-365 "SF" Andre Norton "Night of Masks" (1966)
*F-366 "SF" Andre Norton "The Last Planet"
*F-367 "SF" Philip José Farmer "The Maker of Universes" (1965)
*F-372 "SF" Edward E. Smith "Spacehounds of IPC" (1966)
*F-373 "SF" Howard L. Cory "The Sword of Lankor" (1966)
*F-374 "SF" Jeff Sutton "The Atom Conspiracy" (1966)
*F-375 "SF" Robert A. Heinlein "The Worlds of Robert A. Heinlein" (1966)
*F-377 "SF" Philip K. Dick "The Crack In Space" (1966)
*F-379 "SF" Frank Herbert "The Green Brain" (1966)
*F-382 "SF" Brian W. Aldiss "Bow Down To Nul" (1966)
*F-383 "SF" Lin Carter "Thongor of Lemuria" (1966)
*F-386 "SF" Andre Norton "The Time Traders" (1966)
*F-388 "SF" Samuel R. Delany "Babel-17" (1966)
*F-390 "SF" Jack Vance "The Languages of Pao" (1966)
*F-391 "SF" Andre Norton "The Crossroads of Time" (1966)
*F-392 "SF" Emil Petaja "Saga Of Lost Earths" (1966)
*F-393 "SF" Roger Zelazny "This Immortal" (1966)
*F-396 "SF" Kenneth Bulmer "Worlds for the Taking" (1966)
*F-398 "SF" Eric Frank Russell "Somewhere a Voice" (1966)
*F-399 "SF" Gardner F. Fox "Thief of Llarn" (1966)
*F-400 "SF" Otis Adelbert Kline "Jan of the Jungle" (1966)
*F-402 "SF" Cordwainer Smith "Quest of the Three Worlds" (1966)
*F-403 "SF" Roger Zelazny "The Dream Master" (1966)
*F-406 "SF" Ray Cummings "Tama, Princess Of Mercury" (1966)
*F-407 "SF" Thomas Burnett Swann "Day Of The Minotaur" (1966)
*F-408 "SF" Andre Norton "The Sioux Spaceman" (1966)
*F-412 "SF" Philip José Farmer "The Gates of Creation" (1966)
*F-414 "SF" Emil Petaja "The Star Mill" (1966)
*F-416 "SF" Rex Gordon "Utopia Minus X (1966)
*F-420 "SF" Neil R. Jones "Professor Jameson Space Adventure 1: The Planet Of The Double Sun" (1967)
*F-421 "SF" Donald E. Westlake (as Curt Clark) "Anarchaos" (1967)
*F-422 "SF" Leigh Brackett "The Sword of Rhiannon" (1967)
*F-425 "SF" Poul Anderson "World Without Stars" (1967)
*F-426 "SF" Gordon R. Dickson "The Genetic General" (1967)
*F-427 "SF" Samuel R. Delany "The Einstein Intersection" (1967)
*F-429 "SF" Philip K. Dick "The World Jones Made" (1967)

M Series

*M-116 "SF" Robert P. Mills (ed.) "The Best From Fantasy And Science Fiction, Tenth Series"
*M-119 "SF" Jules Verne "Journey to the Center of the Earth" (1965)
*M-132 "SF" Robert W. Chambers "The King in Yellow" (1965)
*M-137 "SF" Robert P. Mills (ed.) " The Best From Fantasy And Science Fiction, Eleventh Series" (1966)
*M-142 "SF" H.F. Heard "Doppelgangers" (1966)
*M-143 "SF" John W. Campbell "Islands of Space" (1965)
*M-147 "SF" Andre Norton "The Stars Are Ours!"
*M-148 "SF" Andre Norton "Star Born" (1966)
*M-149 "SF" Jack Vance "The Eyes of the Overworld" (1966)
*M-150 "SF" Andre Norton "The Defiant Agents"
*M-151 "SF" Andre Norton "The Last Planet"
*M-152 "SF" H. Warner Munn "King Of The World's Edge" (1966)
*M-153 "SF" A. E. van Vogt "The Weapon Makers" (1966)
*M-154 "SF" John W. Campbell "Invaders from the Infinite" (1966)
*M-155 "SF" Roger Zelazny "Four For Tomorrow" (1966)
*M-156 "SF" Andre Norton "Key Out Of Time" (1966)
*M-157 "SF" Andre Norton "Star Gate" (1966)
*M-162 "SF" Donald A. Wollheim (as David Grinnell) "Edge Of Time" (1966)
*M-165 "SF" Keith Laumer "Worlds Of The Imperium" (1966)

G Series

*G-547 "SF" Austin Hall and Homer Eon Flint "The Blind Spot" (1965)
*G-551 "SF" Donald A. Wollheim and Terry Carr (eds.) "World's Best Science Fiction: 1965" (1965)
*G-570 "SF" Alan Garner "The Weirdstone Of Brisingamen" (1965)
*G-582 "SF" Jules Verne "Journey to the Center of the Earth" (1966)
*G-586 "SF" William L. Chester "Hawk of the Wilderness" (1966)
*G-595 "SF" Andre Norton "Quest Crosstime" (1966)
*G-599 "SF" Andre Norton "Star Guard" (1966)
*G-605 "SF" Larry Maddock "The Flying Saucer Gambit - Agent Of T.E.R.R.A. #1" (1966)
*G-611 "SF" Avram Davidson (ed.) "The Best From Fantasy And Science Fiction, Twelfth Series" (1967)
*G-620 "SF" Larry Maddock "The Golden Goddess Gambit - Agent Of T.E.R.R.A. #2" (1967)
*G-625 "SF" Kenneth Bulmer "To Outrun Doomsday" (1967)
*G-626 "SF" Ursula K. Leguin "City Of Illusions" (1967)
*G-627 "SF" Fritz Leiber "The Big Time" (1967)
*G-630 "SF" Andre Norton "Warlock of the Witch World" (1967)
*G-631 "SF" Neil R. Jones "The Sunless World: Professor Jameson Space Adventure #2" (1967)
*G-634 "SF" Poul Anderson "War of the Wing-Men" (1967)
*G-637 "SF" Philip K. Dick and Ray Nelson "The Ganymede Takeover" (1967)
*G-639 "SF" Edmond Hamilton "The Weapon from Beyond: Starwolf Series #1" (1967)
*G-640 "SF" Thomas Burnett Swann "The Weirwoods" (1967)
*G-641 "SF" Jack Williamson "Bright New Universe" (1967)
*G-644 "SF" Larry Maddock "The Emerald Elephant Gambit : Agent Of T.E.R.R.A. #3"
*G-646 "SF" Andre Norton "The X Factor" (1967)
*G-647 "SF" Murray Leinster "S.O.S. From Three Worlds" (1967)
*G-649 "SF" John Brunner "The World Swappers" (1967)
*G-650 "SF" Neil R. Jones "Space War: Professor Jameson Space Adventure #3"
*G-654 "SF" Andre Norton "Catseye" (1967)
*G-655 "SF" Andre Norton "Witch World" (1967)
*G-656 "SF" John Jakes "When the Star Kings Die" (1967)
*G-660 "SF" A. E. van Vogt "The Universe Maker" (1967)
*G-661 "SF" Jack Vance "Big Planet" (1967)
*G-664 "SF" John Brunner "Born Under Mars" (1967)
*G-667 "SF" David McDaniel "The Arsenal Out Of Time" (1967)
*G-669 "SF" Leigh Brackett "The Coming Of The Terrans" (1967)
*G-671 "SF" John Brunner "Catch A Falling Star" (1967)
*G-673 "SF" Mark S. Geston "Lords of the Starship"
*G-675 "SF" James White "The Secret Visitors" (1967)
*G-677 "SF" Damon Knight "Turning On: Thirteen Stories" (1967)
*G-680 "SF" Kenneth Bulmer "Cycle of Nemesis" (1967)
*G-681 "SF" Neil R. Jones "Twin Worlds: Professor Jameson Space Adventure #4" (1967)
*G-683 "SF" Leigh Brackett "The Big Jump" (1967)
*G-688 "SF" Jack Vance "City Of The Chasch: Planet Of Adventure #1" (1968)
*G-690 "SF" Andre Norton "The Beast Master" (1968)
*G-691 "SF" Andre Norton "Lord of Thunder"
*G-692 "SF" Otis Adelbert Kline "The Swordsman Of Mars" (1968)
*G-693 "SF" Otis Adelbert Kline "The Outlaws Of Mars" (1968)
*G-694 "SF" Thomas Burnett Swann "The Dolphin And The Deep" (1968)
*G-697 "SF" Poul Anderson "We Claim These Stars" (1968)
*G-701 "SF" Edmond Hamilton "The Closed Worlds: Starwolf #2" (1968)
*G-703 "SF" Andre Norton "Victory On Janus" (1968)
*G-706 "SF" Samuel R. Delany "The Jewels Of Aptor" (1968)
*G-709 "SF" John Brunner "Bedlam Planet" (1968)
*G-712 "SF" Anthony Boucher and J. Francis Mccomas (eds.) "The Best From Fantasy and Science Fiction, Third Series"
*G-713 "SF" Anthony Boucher (ed.) "The Best From F & Sf Fourth Series" (1968)
*G-714 "SF" Anthony Boucher (ed.) "The Best From F & Sf Fifth Series" (1968)
*G-715 "SF" Anthony Boucher (ed.) "The Best From Fantasy And Science Fiction, Sixth Series" (1968)
*G-716 "SF" Andre Norton "Web Of The Witch World"
*G-717 "SF" Andre Norton "Daybreak - 2250 A.D. " (1968)
*G-718 "SF" Philip K. Dick "Solar Lottery" (1968)
*G-719 "SF" Neil R. Jones "Doomday on Ajiat: Professor Jameson Space Adventure #5" (1968)
*G-723 "SF" Andre Norton "Star Hunter & Voodoo Planet" (1968)
*G-724 "SF" Philip José Farmer "A Private Cosmos" (1968)
*G-728 "SF" Donald A. Wollheim (as David Grinnell)"Across Time" (1968)
*G-730 "SF" Alan E. Nourse "Psi High And Others" (1968)
*G-733 "SF" Edgar Rice Burroughs "At the Earth's Core" (1968)
*G-734 "SF" Edgar Rice Burroughs "Pellucidar" (1968)
*G-735 "SF" Edgar Rice Burroughs "Tarzan Of Pellucidar" (1968)
*G-736 "SF" Edgar Rice Burroughs "Tarzan At The Earth's Core" (1968)
*G-737 "SF" Edgar Rice Burroughs "Back to the Stone Age" (1968)
*G-738 "SF" Edgar Rice Burroughs "Land of Terror" (1968)
*G-739 "SF" Edgar Rice Burroughs "Savage Pellucidar" (1968)
*G-740 "SF" Fred Saberhagen "The Broken Lands" (1968)
*G-745 "SF" Edgar Rice Burroughs "The Moon Maid" (1968)
*G-748 "SF" Edgar Rice Burroughs "The Moon Men" (1968)
*G-753 "SF" Alan Garner "The Moon of Gomrath" (1968)
*G-756 "SF" Alexei Panshin "Star Well" (1968)
*G-758 "SF" Thomas Burnett Swann "Moondust" (1968)
*G-761 "SF" John Brunner "Catch A Falling Star" (1968)
*G-762 "SF" Alexei Panshin "The Thurb Revolution" (1968)
*G-766 "SF" Edmond Hamilton "World of the Starwolves: Starwolf #3" (1968)

H Series

*H-15 "SF" Donald A. Wollheim and Terry Carr (eds.) "The World's Best Science Fiction:: 1966
*H-18 "SF" Jeff Sutton "H-Bomb Over America" (1966)
*H-19 "SF" Frederik Pohl (ed.) "The If Reader of Science Fiction" (1966)
*H-26 "SF" Avram Davidson (ed.) "The Best From Fantasy And Science Fiction, 13th Series" (1967)
*H-30 "SF" Clifford D. Simak "City" (1967)
*H-33 "SF" Andre Norton "Moon of Three Rings" (1967)
*H-38 "SF" Fritz Leiber "The Swords of Lankhmar" (1968)
*H-39 "SF" Philip K. Dick "Eye in the Sky" (1968)
*H-41 "SF" Jules Verne "Into The Niger Bend" (1968)
*H-42 "SF" Clifford D. Simak "Why Call Them Back From Heaven? " (1968)
*H-43 "SF" Jules Verne "The City in the Sahara" (1968)
*H-49 "SF" Jules Verne "The Begum's Fortune" (1968)
*H-52 "SF" Jules Verne "Yesterday and Tomorrow" (1968)
*H-54 "SF" R. A. Lafferty "Past Master" (1968)
*H-58 "SF" Gertrude Friedberg "The Revolving Boy" (1968)
*H-60 "SF" Jules Verne "Carpathian Castle" (1968)
*H-62 "SF" Wilson Tucker "The Lincoln Hunters" (1968)
*H-67 "SF" Jules Verne "The Village in the Treetops" (1968)
*H-72 "SF" Joanna Russ "Picnic on Paradise" (1968)
*H-73 "SF" Fritz Leiber "Swords Against Wizardy" (1968)
*H-78 "SF" Jules Verne "The Hunt for the Meteor" (1968)
*H-79 "SF" Bob Shaw "The Two-Timers" (1968)
*H-84 "SF" Andre Norton "Sorceress of the Witch World" (1968)
*H-86 "SF" D. G. Compton "Synthajoy" (1968)
*H-89 "SF" John Macklin "Dimensions Beyond The Unknown"
*H-90 "SF" Fritz Leiber "Swords in the Mist" (1968)
*H-92 "SF" A. E. van Vogt "The Far-Out Worlds of A. E. van Vogt" (1968)
*H-102 "SF" Edward E. Smith "Subspace Explorers" (1968)
*H-105 "SF" James H. Schmitz "The Demon Breed" (1968)

K Series

*K-154 "SF" George R. Stewart "Earth Abides" (1962)

A Series

Ace Books published its A series of books from about 1966 to 1968, priced at 75 cents.

*A-3 "SF" Bernard Wolfe "Limbo" (1966)
*A-4 "SF" J. R. R. Tolkien "The Fellowship of the Ring" (1965)
*A-5 "SF" J. R. R. Tolkien "The Two Towers" (1965)
*A-6 "SF" J. R. R. Tolkien "The Return of the King" (1965)
*A-8 "SF" John Myers Myers "Silverlock" (1966)
*A-10 "SF" Terry Carr and Donald A. Wollheim (eds.) "The World's Best SF: 1967" (1967)
*A-12 "SF" Terry Carr (ed.) "New Worlds of Fantasy" (1967)
*A-13 "SF" James H. Schmitz "The Witches of Karres" (1968)
*A-15 "SF" Terry Carr and Donald A. Wollheim (eds.) "World's Best SF: 1968' (1968)
*A-16 "SF" Alexei Panshin "Rite of Passage" (1968)
*A-17 "SF" Avram Davidson (ed.) "The Best From Fantasy & Science Fiction, 14th Series" (1968)
*A-19 "SF" Piers Anthony and Robert E. Margroff "The Ring" (1968)
*A-25 "SF" Edgar Rice Burroughs "The Outlaw of Torn" (1968)
*A-29 "SF" James Blish and Norman L. Knight "A Torrent of Faces" (1968)

N Series

*N-3 "SF" Frank Herbert "Dune" (1965)

References

* [http://people.uncw.edu/smithms/ACE.html Ace Image Library] . Contains images of most covers for both the singles and doubles.
*Tuck, Donald H. "The Encyclopedia of Science Fiction and Fantasy: Volume 3", Advent: Publishers, Inc., 1982. ISBN 0-911682-26-0. Lists all ACE sf titles, single and double, published through 1968.

The following references have not been seen:

*Peters, Harold R. "Science Fiction, Fantasy & Horror in the Ace Letter-Series Editions: A Collector's Notebook", Silver Sun Press, 1996.