requiring some specific browser just to input address

BookWyrm is a secondary source, so I don’t think it’s a good idea. Personally, I’d link to:

• The book’s website, if there is (which usually just links to amazon)
• Wikipedia page
• OpenLibrary

As for where to buy books, I’ve recently heard of Libreture, which have DRM-free books (see other DRM-free book source), though its database might be lacking because it’s rather new.