I don't think requests for citations by replying commenters is worthwhile. If a comment piques your interest, or simply your curiosity, Google Scholar can prov

I don't think requests for citations by replying commenters is worthwhile. If a comment piques your interest, or simply your curiosity, Google Scholar can provide support (or disproof) readily and to a much greater, and especially more broad ranging, extent than is possible in a comment. And you will find a citation quicker than waiting for the original commenter to provide one, even if the person actually replies with a citation rather than just ignoring you. If you can't find support, then that is a good point to bring up in a reply. ADDED: Please note that I am not against people providing links to supporting information. The best way to get an upvote from me is to provide a link to an interesting paper or site.