How do you cite quotes?

So I'm writing a persuasive essay on why Lord of the Flies should or should not be banned and I want to quote one of the challengers in my opening statement. Problem is, I'm not sure how to cite the quote. All of the sources I've looked at (which were online) said simply that they were a challenger from Nebraska and nothing else. How do I cite the quote if I don't know who said it? Do I add in the URL in parentheses after the quote or what? Thanks in advance!