It's actually very hard to just post anything on Wikipedia these days - there are many editors and checks to make sure that what is posted is clearly documented. But I just gave that as an example. Here are some more links.

US Department of State: https://www.state.gov/russias-filtration-operations-and-forced-relocations/

New Yorker: https://www.newyorker.com/magazine/2022/10/10/inside-russias-filtration-camps-in-eastern-ukraine

Forbes: https://www.forbes.com/sites/ewelinaochab/2022/10/30/what-are-putins-filtration-camps-and-why-are-they-concerning/?sh=6d6a80e03d5f

You can find many more by searching. I would also like to remind you that Russia has nearly shut down all independent media (e.g., https://www.state.gov/media-crackdown-in-russia/), curates the story about its "special military operation" very closely, and is not a democracy, so any ".ru" links should be treated with extreme suspicion if not outright dismissed.