L. Sprague De Camp books in order
18 books in the catalogue, about 115 hours of reading in all; the shortest takes 3 hours and the longest 13 hours.
2 series and 13 standalone books in the catalogue.
Novarian series
6 books The Goblin Tower length not known
The Clocks of Iraz length not known
The Fallible Fiend 3.2 h The Reluctant King length not known
The Unbeheaded King 3.4 h 
The Honorable Barbarian 4.0 h Harold Shea
14 books The Mathematics of Magic length not known
The Castle of Iron length not known
The Incomplete Enchanter length not known
Wall of Serpents length not known
The Compleat Enchanter length not known
The Complete Compleat Enchanter length not known
Sir Harold and the Gnome King length not known
The Enchanter Reborn 5.9 h Sir Harold of Zodanga length not known
The Exotic Enchanter 5.3 h 
The Mathematics of Magic: The Enchanter Stories of L. Sprague de Camp and Fletcher Pratt 9.4 h The Green Magician length not known
The Roaring Trumpet length not known
The Wall of Serpents length not known
Standalone books
Lest Darkness Fall 3.8 h 
Swords and Sorcery 3.4 h 
The Ancient Engineers 7.6 h 
Conan of Cimmeria 3.5 h 
Conan of the Isles 3.5 h 
The Compleat Enchanter 8.8 h 
Conan the Barbarian 3.3 h 
Dragon Tales 5.8 h 
Science Fiction A to Z 11.9 h 
The Fantasy Hall of Fame [22 stories] 7.9 h 
The Golden Years of Science Fiction 13.3 h 
The Fantasy Hall of Fame [30 stories] 10.3 h 
The Mammoth Book of Classic Science Fiction 10.5 h