[1] Univ Gadjah Mada, Dept Surg, Div Neurosurg, Yogyakarta, Special Region, Indonesia
[2] Muhammadiyah Univ Hosp, Div Neurosurg, Malang, East Java, Indonesia
[3] Jayapura Gen Hosp, Div Neurosurg, Jayapura, Papua, Indonesia
[4] Dr Midiyato Suratani Naval Hosp, Div Neurosurg, Tanjung Pinang, Riau Islands, Indonesia
[5] Undata Gen Hosp, Div Neurosurg, Palu, Central Sulawes, Indonesia
[6] Univ Gadjah Mada, Dept Hlth Policy & Management, Special Region Of Yogyak, Indonesia