This is the link to purchase the Standard of Perfection. http://www.amerpoultryassn.com/APA_ShoppingMall3.htm As you can see, you can either purchase the color edition for $59, or the black and white edition, for $14. I myself purchased the black and white edition, and am perfectly happy with it. If I need color pictures, either BYC or Feathersite, is full of far more color pictures than are in the SOP. So if you are serious about your birds, you should consider purchasing this book.