For scholarly articles, access to JSTOR, the ProQuest dissertations database, Google Scholar and references to academic studies are the best sources to consult. It’s also helpful to track down the work of experts quoted in the serious press. These will provide a broad overview and offer an historical overview from different theoretical perspectives. Searches  in Google Books, to the extent that Google provides the full-text, can be fruitful. If the full-text is not handy on Google Books, use the library link and borrow the title if needed either through your institutional library or by referring to World Cat for a local source.