Books like Citizen of the Galaxy
Robert A. Heinlein
Citizen of the Galaxy is 280 pages, about 5 hours 8 minutes at 250 words a minute.
12 books to read next
How long each takes
The Martian Chronicles 4.8 h 
Gateway 5.7 h 
Kindred 5.3 h 
Slave 6.4 h 
Dune Messiah 5.1 h 
Illuminae 11.2 h 
The Algebraist 9.2 h 
Record of a Spaceborn Few 6.6 h 
The Caves of Steel 4.5 h 
Children of the Mind 7.0 h 
Robot Dreams 8.2 h 
Uncle Tom's Cabin 8.3 h Bar height shows length. Estimated at 250 words a minute.