Given that Google, on occasion, shuts down their little projects- should I be using their Books subsite as a source?
I did it twice in an answer here, and I get antsy with overly-long generated links as it is [one aspect could be a session-id that's going to expire, and negate the link?], and have done it a few times recently.
And I don't want to link to another 'project' of Google's that will disappear in two years. Articles here should be as permanent as possible.
The alternatives to Google Books are often else-country from publisher and sketchy at best.