How to create a child page that has the same content type as parent page? I enabled the Book module on drupal 7 and created 2 new content types. Let said I created a new "content type A" and "content type B", and keep the book module content type as "Book page". The issue I have is that whenever I adding a child page on a "Content type A" or the "Content type B" page, these child pages are "Book page" content type. How to keep these child page the same content type as parent page?

PS: I see there is a "Books" setting under "content > books" tab. But it only allow me to select one content type as child page.
I found a module that does the job, which is Book made simple. This module add the setting on content type and have the option for "SELECT CONTENT-TYPES ALLOWED AS CHILD.", "SELECT CONTENT-TYPES ALLOWED AS PARENT" and "Other Settings". Then a dropdown listbox will be added in the books link like the one on screenshot. I hope Drupal 8 has a similar feature like this. 

PS: One of the issue is "Printer" module also print "Add child page" on each page.