Books like Farmer in the Sky
Robert A. Heinlein
Farmer in the Sky is 221 pages, about 4 hours 3 minutes at 250 words a minute.
12 books to read next
How long each takes
Red Mars 10.9 h 
The Stars, Like Dust 4.2 h 
The Martian Chronicles 4.8 h 
The Illustrated Man 4.6 h 
The Naked Sun 4.2 h 
The Foundation Trilogy 11.1 h 
A Canticle for Leibowitz 5.9 h 
Ringworld 6.2 h 
Lord of Light 5.1 h 
A Fire Upon the Deep 11.1 h 
Seveneves 15.8 h 
The Robots of Dawn 8.2 h Bar height shows length. Estimated at 250 words a minute.