I don't know about these links and can't view them from here. But you can download a reader app from b&n that will run on windows, mac or I-Phone. So you don't even need a nook if you always have one of those handy and don't mid reading on them. For recreational reading I prefer a non-backlit screen.
You can also download PDF & EPUB from google-books and use the b&n reader. It's free whether you buy a nook or not.
I don't buy products I can't even replace the battery in!
Allen
Allen Jessup
Engineering Specialist / CAD Manager