I've seen a couple of 'most mentioned' pass by in recent years, all seem to have a different algorithm & outcome of all the most mentioned books. If I compare yours to i.e. <a href="http://hackernewsbooks.com/" rel="nofollow">http://hackernewsbooks.com/</a> the top mentioned book is vastly different than the one on your site. I mean this is not a problem at all, just found this interesting.