I bought the HV and HE the book and have already treated otitis my son, a nail fungus (more effective than chemical treatment I had for over a year), and d psoriasisme 'a friend. I'm not a pro, and explanations and dosages seemed to me sufficiently clear and precise for that I do not even. I'm so happy with this book, which I have already offered to 3 people. Then you find the right place to find the essential oils and bottles!