1. Department of Neurosurgery, Dr. Soeradji Tirtonegoro Central Public Hospital, Klaten, Indonesia
2. Department of Neurosurgery, Faculty of Medicine, Mataram University/West Nusa Tenggara General Hospital, Mataram City Lombok Island, Indonesia
3. Department of Neurosurgery, Faculty of Medicine, Udayana University/Prof. Dr. I Goesti Ngoerah Gde Ngoerah Hospital, Denpasar, Indonesia
4. Department of Neurosurgery, Faculty of Medicine, Sebelas Maret University/Dr. Moewardi General Public Hospital, Surakarta, Indonesia.