You check the links/references it gives you.

Gemini does a pretty good job of this because it doesn't seem to have much built-in knowledge. Instead, it just searches the Internet on your behalf and returns summarized results with links to where it got that specific information.

I use it to search for scientific research all the time and the summaries often aren't detailed enough so I actually click on those links. I've yet to encounter a situation where it fucked that up (invented links that don't exist) but I have heard about it happening.

So far, the summaries have seemed to be pretty spot-on when it comes to biology papers 🤷