Mastering Go Second Edition, published by Packt
The Amazon.com page of the book is here. You can also visit the web page of the book at Packt.
There is a 3rd edition of Mastering Go! You can find more about it here.
If you have already purchased a print or Kindle version of this book, you can get a DRM-free PDF version at no cost.
Simply click on the link to claim your free PDF.