1. The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA;
2. Department of Neurosurgery, Ankara University Faculty of Medicine, Ankara, Turkey;
3. Department of Neurosurgery, Yeditepe University Faculty of Medicine, Istanbul, Turkey;
4. Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA;
5. The Neurosurgical Atlas, Carmel, Indiana, USA