Jack Williamson books in order
8 books in the catalogue, about 79 hours of reading in all; the shortest takes 5 hours and the longest 17 hours.
8 standalone books in the catalogue.
Standalone books
Darker Than You Think 4.9 h 
The Starchild Trilogy 8.1 h 
The Science Fiction Hall of Fame -- Volume Two A 10.5 h 
Before the Golden Age 16.7 h 
Isaac Asimov's Masters of Science Fiction 5.3 h 
The Golden Years of Science Fiction 13.3 h 
The Mammoth Book of Classic Science Fiction 10.5 h 
The Mammoth Book of Golden Age Science Fiction 9.4 h