If so, does the article accurately represent their information? Is anything in the source material overinflated or ignored? You may not have free access to a source through the internet, but your local library may be subscribed to the source. Remember, if you need access to information, your librarian can help!
A source that extensively cites itself is the scholarly equivalent of a person who says, "You can trust my word because I said you can." If you follow a citation to its source and it opens another page on the same site or a closely related site, consider verifying the cited information elsewhere.