I want to find out more information and start to build up a library soon, and I know a reference library may not come cheap with brand new vet college books. And also other type bird books on how to build all natural cages for them if possible, what materials to use, and how to turn it into a playpen for them, and what dimensions of wood is needed with what equipment. Carpentry for birds. We have parakeets and a cockatiel and outdoor birds too.