Tactical Fly Fishing
One of the best written books on modern fly fishing techniques including an emphasis on (but not limited to) Euro nymphing, and it gives good insight into competition fishing. I balances scientific understanding with very practical applications; it is simply excellent! I have eagerly read it at least three times and glean a bit more with each reading. Would highly recommend to anyone serious about fly fishing. It expands upon what is included in Devin's excellent and well produced videos and posts. It is truly noteworthy.