Sorting these covers by decade
Foundation by decade
Isaac Asimov
46 covers from 60 printings with a known year, 2010s back to 1950s
2010s
4 covers · 2 of 4 printings say paperback · 4 publishers, HARPER COLLINS and Golden Branch among them · 3 languages
2000s
16 covers · 14 of 20 printings say paperback · 16 publishers, Plaza & Janés and Aleph among them · 4 languages
1990s
5 covers · 3 of 5 printings say paperback · 5 publishers, HarperCollins Publishers India and Mondadori among them · 3 languages
1980s
10 covers · 8 of 11 printings say paperback · 10 publishers, Bruguera and Plaza & Janes among them · 4 languages
1970s
2 covers · 2 publishers, Avon Books and Panther Book among them
1960s
6 covers · 8 of 20 printings say paperback · 7 publishers, Panther and Avon among them · 2 languages
1950s
3 covers · 2 of 4 printings say paperback · 4 publishers, Harper. 1 Paperback(s) and HarperCollins Publishers India among them
Covers from Open Library, each in the decade of the earliest printing that carries it. What the catalogues never scanned is missing here too. See the whole wall.
