You can still use it as a source, you can't transcript it (copy). You can paraphrase the information by rewriting it into your own words. Be sure to include a citation when alluding to an idea or wording that's not your own, even if you have to do this multiple times. For example, don't just cite the end of a paragraph. If you use a phrase in a sentence, then cite the sentence.
One other alternative is to search the internet for another source. I talked about perplexity AI (
https://www.perplexity.ai/) a few weeks before you can paste a sentence or two, and it will try to find online sources for the information. It doesn't always work, but is something you can easily try. Of course, you can google it.
I don't know how familiar you are with Google, but if you use
https://books.google.com/ Goolge books link, it will search for books containing the information online. Some are not viewable online, but others are. More and more published books are coming online, so there is a good chance it might be viewable online.