For me, when it came to long term papers I have always basically just plagarized all over the internet... but you just re-word all of the ideas and points. You don't necessarily need a written copy of someone else's term paper. Just use bullshitting skills, find good websites that are relevant to your topic and just re-word all of it. Technically, you're not doing anything that can be punishable. You are stealing ideas... but it would be impossible to prove precisely where they came from. Some instructors will use a website that scans written work for likeness on the internet. I don't remember what it was called... oh yeah,
http://www.turnitin.com, I think.
I took a course where all of our work had to be submitted through that website and scanned for likeness. It's incredible how accurate that shit is, but like I said, if you're re-wording your work there is no way for even that site to bust you. I had a number of papers that were complete regurgitations of ideas of websites I used... and turnitin only identified like a 2-3% likeness with the internet. Most instructors will give you extra credit for having a likeness that low. It's when you are over 10% that they start looking at your work very closely for plagarism.