Those links appear at the bottom of the page. So unless the author added them just now after seeing your comment... I'm glad plagiarism by itself is not a crime, there are some real witch hunters out there. (You can find a lot of them by looking up Einstein's history.) If I were Google I'd probably favor an HTML page over a PDF too when the content is more or less the same.
He/She (there's no author name) has added them after seeing this comment - I had the tab open for an hour now and there's no attribution there: http://d.pr/6mlz (in case you're wondering about the bizarre colorful thing, it's YouTube! It's blocked in Iran and instead of the video, they display garbage links to government websites)