Riverworld is a 7-book series with 4 primary works first released in 1971 with contributions by Philip José Farmer and philip-jose-farmer.
1971 • 1 Reader • 244 pages
1980 • 19 Readers • 496 pages • 3.8
1983 • 19 Readers • 368 pages • 3.1
1979 • 1 Reader • 303 pages
1993 • 1 Reader • 326 pages • 3
2010 • 336 pages