Are these books outdated?

[Stefan Wahren]

Am 11.08.2016 um 05:52 schrieb Raul Piper:
> Pdfdocs !!
> Hmm that would be a nice Idea to collate all the Documentation of the
> kernel  into the pdfs and make a book out of it for any kernel version
> we want !
> Thanks !

There is a german book [1] which handles Kernel 4.x and device trees. 
But i don't know if any translation is planned.

[1] - https://ezs.kr.hsnr.de/TreiberBuch/