Riverworld is a 7-book series with 4 primary works first released in 1971 with contributions by Philip José Farmer and philip-jose-farmer.
1980 • 13 Readers • 496 pages • 3.8
1983 • 14 Readers • 368 pages • 3.3
1979 • 1 Reader • 303 pages
1993 • 1 Reader • 326 pages • 3
2010 • 336 pages