Updated Java Play books\tutorials and usage references

What are the best updated books\posts regarding Java Play?
Is there any list of companies that currently use Java Play in production?


https://www.playframework.com/ has a listing of some of the companies using play framework extensively. There are probably books out there for play framework, however I found the documentation quite comprehensive for most of my needs. The documentation covers everything from beginner to advanced on a host of topics related to the play framework along with its auxiliaries (Akka, WS, EBean etc.)

cc @marcospereira