August Derleth books in order
10 books in the catalogue, about 72 hours of reading in all; the shortest takes 3 hours and the longest 19 hours.
10 standalone books in the catalogue.
Standalone books
The Lurker at the Threshold 3.5 h 
The Mask of Cthulhu 3.4 h 
Thrillers and More Thrillers 3.8 h 
Tales of the Cthulhu Mythos, Volume 1 4.4 h 
The Nightmare Reader 5.5 h 
The Twelve Crimes of Christmas 4.7 h 
Isaac Asimov Presents Tales of the Occult 6.5 h 
Murder for Halloween 6.6 h 
The Vampire Archives 18.9 h 
Zombies! Zombies! Zombies! 14.9 h