1. John Stroger Hospital of Cook County, Department of Anesthesiology and Pain Management, Chicago, USA + University of Banja Luka, Medical Faculty, Department of Clinical Pharmacology, Banja Luka, Republic of Srpska, Bosnia and Herzegovina
2. University of Banja Luka, Medical Faculty, Department of Clinical Pharmacology, Banja Luka, Republic of Srpska, Bosnia and Herzegovina