Allen Carr books in order
7 books in the catalogue, about 30 hours of reading in all; the shortest takes 2 hours and the longest 9 hours.
7 standalone books in the catalogue.
Standalone books
The Easy Way to Stop Smoking (2 editions) 2.4 h 
The Only Way to Stop Smoking Permanently 8.8 h 
Allen Carr's Easy Way to Stop Smoking (2 editions) 3.6 h 
Allen Carr's Easy Way to Be Successful 2.4 h 
The Easy Way to Stop Drinking 5.0 h Stop Smoking with Allen Carr 3.5 h Allen Carr's Easy Way to Quit Emotional Eating 4.7 h