Why so few 15C/11C application and program books?

[Gamo]

The HP-15C gear toward to advance scholarship stuff so it got the
HP-15C Advanced Functions Handbook that cover many numerical analysis that includes applications program based on specialized calculations. So this book is just like a Solutions Handbook with detail on functions and computation limit.

I think that since HP-11C already got the Solutions Handbook that can
be use on the 15C so then HP didn’t decide to make it own 15C Solutions
Handbook.

Gamo