Books like KGB
Christopher M. Andrew, Christopher Andrew, Oleg Gordievsky
KGB is 704 pages, about 12 hours 54 minutes at 250 words a minute.
12 books to read next
How long each takes
Spet︠s︡operat︠s︡ii 9.3 h 
By Way of Deception 7.0 h 
Spycatcher 7.2 h 
The Main Enemy 10.6 h 
Deep Undercover 6.2 h 
First Person 3.9 h 
Kgb/CIA 3.5 h 
The Hunt for Red October 8.8 h 
The Secret Speech 8.4 h 
Casino Royale 3.5 h 
The Matarese Circle 11.0 h 
Along Came a Spider 8.2 h Bar height shows length. Estimated at 250 words a minute.