1. University of Florida College of Medicine, Gainesville, Florida, USA
2. Krankenhaus Neuwerk “Maria von den Aposteln,” Mönchengladbach, Germany
3. Louisiana Pain Specialists, New Orleans, Louisiana, USA
4. Metro Pain Group, Victoria, Australia
5. Ainsworth Institute of Pain Management, New York, New York
6. Institute for Neuromodulation, Boca Raton, Florida, USA