[Alex3917]

Correct. It's conceivable that you could find a secondary source in their reading list that links to a primary source, but in practice going through their list of sources would be much slower than just doing the search yourself, meaning that site has zero utility in practice. (Assuming you care about the information you're getting being true, if you're writing a middle school paper about penguins then it probably gives you enough plausible deniability for having done the work, but for anything else there isn't much point.)