Here are some links that have some more great information about Quaker Parakeets.
Quakerparrots.com is a site devoted to the knowledge and care of Quaker Parrots. They have lots of articles as well as a question and answer forum. They also have a book that I have read and would recommend to anyone looking for more good information.
This guy has been devoting his life to Quakers for over 15 years now! Quakerville.com He has a lot of great pictures on this site as well.
BirdsnWays is a complete guide to Pet Birds, Pet Parrots & Exotic Birds. Lots of good information on Quakers there!
There is also lots of information and pictures available regarding Quaker Parrots these days available on the internet. Just Google Quaker Parakeet!