Ace Science Fiction Doubles ~ D-Series
1953 ~ 1961

Of all the gimmicks used to sell paperback books the Ace
Doubles series is without a doubt my favorite! The doubles
first saw print in the D-Series (1952-1965) of Ace Books.
The first complete Sci-Fi Double is D-31 (1953) and during
the next nine years there were a total of 75 published in the
D-Series. Here's the covers to about a third of them!

Cover art by Norman Saunders, Ed Emshwiller, Robert Shultz,
Stanley Meltzoff, Ed Valigursky, Richard Powers and others!