They are just the articles you wrote in class. Now that cryptos have become famous, everything has become costly as hell, so the articles you wrote in class for free now cost 500 dollars, the events that used to cost 500 dollars now cost 50.000$, and I could go on forever. Note that IcoBox offers you to write your WhitePaper for 8 BTC ! lol and that's a little more than the article you wrote in 101, but not that much more.