I hope you didnt take offense.
Oh no, not at all.
There was at first a B4A Beginner's Guide, which became huge.
I splitted it into a Beginner's Guide and a User's Guide.
The latest Beginner's Guide had 390 pages and the User's Gide 209.
Then came B4i, B4J and B4R, and a Beginner's Guide for each.
As these products are very similar there was mach redundant content.
I changed then my mind and began to write the B4X Booklets covering all products.
I consider these as tomes, Getting Started, IDE, Basic Languge, Visual Designer.
Writing one book covering the whole subject would, in my mind, be too big and less efficient.
There exist a commercial
B4A Book written by Wyken Seagrave as alrady suggested in post #2.