Robert Silverberg books in order
48 books in the catalogue, about 353 hours of reading in all; the shortest takes 3 hours and the longest 16 hours.
1 series and 46 standalone books in the catalogue.
Majipoor series
5 books 1 
Lord Valentine's Castle 8.6 h 
Tales of Majipoor 6.4 h
Lord Valentine's Castle 8.6 h 2 Majipoor Chronicles length not known
3 Valentine Pontifex length not known
4 The Mountains of Majipoor length not known
8 Tales of Majipoor 6.4 h Standalone books
The Hugo Winners 5.9 h 
The Hugo Winners, Volumes One and Two 15.6 h 
The Gate of Worlds 4.5 h 
Hawksbill Station 3.4 h 
Nightwings 3.5 h 
The Man in the Maze 3.8 h 
Up the Line 4.7 h 
Downward to the Earth 3.5 h 
The Science Fiction Hall of Fame 10.2 h 
Tower of Glass 3.8 h 
A Time Of Changes 3.9 h 
Son of Man 3.9 h 
The World Inside 3.5 h 
Dying Inside 4.7 h 
The Book of Skulls 4.1 h 
New Dimensions 3 3.9 h 
Galaxy 8.5 h 
Microcosmic Tales 6.0 h 
The Arbor House Treasury of Horror and the Supernatural 11.0 h 
Majipoor Chronicles 5.8 h 
Caught in the Organ Draft 5.1 h 
The Fantasy Hall of Fame [22 stories] 7.9 h 
Machines That Think 11.5 h 
Supermen 6.4 h 
Baker's Dozen -- 13 Short Science Fiction Novels 10.5 h 
Sailing to Byzantium 5.5 h 
The Fantasy Hall of Fame [30 stories] 10.3 h 
Foundation’s Friends 9.0 h 
The Best Horror Stories 7.3 h 
The Horror Hall of Fame 7.6 h 
The New Hugo Winners, Volume II 6.8 h 
The Ugly Little Boy 6.5 h 
Isaac Asimov Presents The Great SF Stories 25 6.7 h 
The Mammoth Book of Fantastic Science Fiction 9.9 h 
The Positronic Man 4.6 h 
Legends (2 editions) 7.3 h 
Far Horizons 8.9 h 
The Living Dead 8.9 h 
Warriors 13.5 h 
Alien Contact 7.3 h 
Zombies! Zombies! Zombies! 14.9 h 
Other Worlds Than These 7.3 h 
Wastelands 2 6.2 h 
Loosed Upon the World 10.9 h 
Infinite Stars 9.9 h 
The Best of Subterranean 13.8 h