Absolutely Positively Gun Dog Training, Robert Milner
And I would also add to read any other books you run across. I’ve read a bookshelf full and there is no book or method that I follow 100%. But every time I read another book I pick some new I like or pick up a trick that makes something I’m already doing work better.
Something else that I bet is worth checking out is the Upland Institute video series with Justin Mcgrail. That have videos that seem to cover it all from the puppy stage on. I haven’t seen the videos yet but I’ve heard Justin a bunch and he knows his stuff.