I put up a post about the guide in the link about a month or two ago. If your looking for something to throw in your blind bag and want to be able to ID a bird before you shoot it, this is the guide to use. The LeMaster book is recommended by a lot of people but you need the duck bill in hand to use the guide. The guide in the link has in flight detail listed and flock formation information as well. It "waterproof" as well. Price is cheap as well. I picked mine up at a refuge in NC and gave a few away to people already.