I'm just one person sharing what I can, but there is a whole world of references out there. I also believe teaching my members to find the information on their own is my job. If the people who follow me can't do my job in the future then I have failed as a leader. Here are some of my favorite spots to "Go Fish".
A lot of hater will try to tell you there aren't any medical studies on essential oils. They are full of, well, you know what they are full of. Hop on over to Pubmed and type in some keywords. May I recommend the scientific name of an oil, a chemical constituent, or ease in with a broad search like "Bioavailability".
The internet is full of people trying to tell you what to do who really have no business doing so. (I'm one of those jerks. You're welcome!) The scholar version of Google limits your search and guides you towards scholarly articles.
If you're looking for printed publications or apps for your phone which are specific to Young Living, Life Science Publishing has a lot of material. They have the Complete Guide to Essential Oils in several formats, and even have a copy for your animal friends. These are great to quickly reference specific oils, blends, application techniques, and more.
Don't have time to sit down and read a book and need some reference material on the go? The Revolution Oils Podcast has a ton of information which is easy to fit in with your busy lifestyle. Give it a listen!
If you're a science buff like me you might like to follow two of my favorite scientific essential oilers on Facebook.
Lindsey Elmore, aka the Farmacist, is a chemist and a pharmacist who uses her knowledge to break down the science behind essential oils. I'm just starting to dive into her material so stay tuned for additional details.
Dr. Doug Corrigan is also one of my favorites. He holds a PhD in Biochemistry and Molecular Biology. If there's anyone out there I enjoy hearing discuss essential oils or who writes solid material, this is the guy. Check out his Facebook Group "Shedding Light on Essential Oils". His eBook of FAQs is also a well composed resource.
Both Lindsey and Dr. Doug have been featured in podcasts with Revolution Oils, so check those out as well.