1. University of Banja Luka, Faculty of Forestry, Vojvode Stepe Stepanovica 75a, 78000 Banja Luka, Republic of Srpska, Bosnia and Herzegovina
2. University of East Sarajevo, Faculty of Technology, Karakaj 34A, 75400 Zvornik, Republic of Srpska, Bosnia and Herzegovina
3. University of Niš, Faculty of Technology, Bulevar Oslobodenja 124, 16000 Leskovac, Serbia