The latter for blogs would depend on patience, and effort and/or luck. I.e. find a relevant blog, and either the blogger brings up the subject you're interested in, so you can ask a question, or---and this is probably the most important thing you can do, whatever forum type you do it in---become part of that blog's community. After a certain point you'll be able to ask the author directly and perhaps have it become the basis of a blog positing.

If you can find a community you'll be a long ways towards being a position to get your needs satisfied.