Books like David Starr - Space Ranger
Isaac Asimov
David Starr - Space Ranger is 168 pages, about 3 hours 5 minutes at 250 words a minute.
12 books to read next
How long each takes
Star Gate 3.5 h 
Dragonflight 5.7 h 
Extras 7.7 h 
The Invasion 3.5 h 
Have Spacesuit--Will Travel 4.7 h 
House of Stairs 3.1 h 
Double Star 3.1 h 
The Visitor 3.5 h 
The Time Traders 3.2 h 
Space Cadet 4.4 h 
Red Planet 3.9 h 
Podkayne of Mars 3.8 h Bar height shows length. Estimated at 250 words a minute.