There are a lot of sites on the internet that will tell you the "benefits" of essential oils. Most of them don't provide citations and most are repeating the same information without citation, they aren't coming from evidence based, peer reviewed, scientific sources.
I had a hard time finding some, but they are out there. Here are some links I found helpful while doing this paper. You can cut and paste them into your browser and check them out!
http://www.drugs.com/npp/wintergreen.html (this site has most of the required oils)