1. Bedrocan International, Veendam, The Netherlands.
2. Department of Pharmacoepidemiology and Clinical Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
3. Division of Laboratory Medicine & Pharmacy, Department of Clinical Pharmacy, University Medical Center, Utrecht, The Netherlands.
4. Hazekamp Herbal Consulting BV, Leiden, The Netherlands.