This is the one I keep coming back to, I love the alphabetical section with tremendous detail on the selected essential oils. It seems to me a totally professional text and the most useful, although I have Battaglia and various others including Jane Buckle, which would be my top three. I am also a nurse but I don't share the first reviewer's views. It is obviously written by someone with tremendous experience and is very well referenced. It would always be nice to have more information, eg on dementia care, (my field), which the reviewer mentions, but in fact there is little research based information on that anyway! I unhesitatingly recommend it.