Eszter wrote:

One method I use to try to track down sources is to type into Google (using quotes) one of the more complex sentences in the paper. Since Google now indexes MSWord and PDF in addition to HTML, this is often helpful.

I recommend leaving off the first few words of a sentence before searching for it, and pick sentences buried in paragraphs. If the student bothers to edit anything at all, beginnings and endings are the most likely. Lori