1. University of Belgrade, Faculty of Medicine, Belgrade, Serbia + Clinical Center of Serbia, Center for Anaesthesiology and Reanimatology, Belgrade, Serbia
2. Clinical Center of Serbia, Center for Anaesthesiology and Reanimatology, Belgrade, Serbia
3. Military Medical Academy, Clinic for Neurosurgery, Belgrade, Serbia
4. Military Medical Academy, Clinic for Neurosurgery, Belgrade, Serbia + University of Defence, Faculty of Medicine of the Military Medical Academy, Belgrade, Serbia
5. Clinical Center of Serbia, Clinic for Neurosurgery, Belgrade, Serbia
6. University of Belgrade, Faculty of Medicine, Belgrade, Serbia + Clinical Center of Serbia, Clinic for Neurosurgery, Belgrade, Serbia