Just One of Those "Holy Shit" Moments

During my office hours this afternoon, a student called. This student seems intelligent enough, but comes to class only when he feels like it - which, incidentally, has been about four times so far this semester. He had a few questions, he explained, about the current essay assignment. He would have known the answer to all of the questions if he had been in class during the past two weeks, but I answered them without comment. Then he got to this one: "It says on the assignment sheet that we need to use three sources, but only one of them can be an online source. So...what do you want us to use for sources?"