How does one define a non-biased, citation-worthy study?
Determining whether a study is accurate, reliable, unbiased, etc. can actually be quite difficult, particularly for tricky and difficult to measure phenomena.  This is what scientists argue about amongst themselves, and the consensus that emerges is best interpreted as the current best understanding of a subject.

Peer-reviewed publications are a good starting point, because the peer-review process strives to ensure that they are in fact accurate, reliable, unbiased, etc.  The publications are written and reviewed by humans, however, who are not very good at those things, and as such some bad articles get published and some good ones don't.  Likewise, there are many different levels of quality in peer-reviewed journals.  Still, for all its flaws, peer review is a lot better than not-peer-reviewed at filtering out things are are inaccurate, unreliable, badly biased, etc, and thus "peer-reviewed publication" is typically a good heuristic for "probably worth considering as a reasonable source of information."

That is not, however, the end of the story on whether an article is a good source of information.  A good next step is to see what other scientists say who reference the article in their own publications.  One article does not an established fact make; many in agreement do.