I am fortunate to know about a variety of things and, sometimes, know a little more about a few things that the internet doesn't always have accurate, up-to-date information on. For some of these things, my education plays a major role and while a standard bibliography can handle most information taken from textbooks, for example, accurate information can also be found in paywalled publications, ongoing studies and so on. Basically, not everything has an answer on the internet and some things don't even have answers in textbooks.
So, my question is, how should someone answering a question, and needing to give a resource, deal with things that are related to their degree, or other education, or things they have specialized information on, that the internet is still inadequate in providing references for?