I see a listing of what the link lacks. It's not the parent's responsibility to provide references without being asked to do so - gathering resources for this kind of post can easily take 2-3x the effort of writing up the original post, especially if the parent's author hasn't studied the subject formally recently. Also, he doesn't know that there's demand for more references without first posting, and if we expect all such posts to contain references, we discourage their authors from writing them.