Sorting these covers by decade
Rubāʻīyāt by decade
Omar Khayyam
30 covers from 25 printings with a known year, 2000s back to 1870s
2000s
2 covers · 2 publishers, Ljiljan and Rusich among them
1990s
4 covers · 4 publishers, Ketab Corp. and Alternatives among them · 4 languages
1980s
1 cover · 1 publisher, Omega Books
1970s
5 covers · 5 publishers, Éditions Champ libre and Caravan Books among them · 2 languages
1960s
2 covers · 2 publishers, Doubleday and Collier Books among them
1950s
1 cover · 1 publisher, Macmillan
1920s
1 cover · 1 publisher, B. Quaritch
1910s
1 cover · 1 publisher, T.N. Foulis
1900s
2 covers · 2 publishers, s.n. and Donohue among them · 2 languages
1890s
6 covers · 3 publishers, Henry Altemus company and H.S. Nichols among them
1880s
2 covers · 1 publisher, Houghton
1870s
3 covers · 2 publishers, Quaritch and Bernard Quaritch 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.