Books like Improvising Jazz
Jerry Coker
Improvising Jazz is 115 pages, about 2 hours 7 minutes at 250 words a minute.
7 books to read next
How long each takes
The Jazz Theory Book 9.6 h 
The Jazz Musician's Guide to Creative Practicing 2.8 h 
Blues People 4.5 h 
Jazz Arranging Techniques 4.4 h 
A Systematic Introduction to Improvisation on the Pianoforte 2.4 h 
The Jazz Piano Book 5.7 h 
Popular Piano Self-taught 2.2 h Bar height shows length. Estimated at 250 words a minute.