1. 1 PI Veterinary Institute of the Republic of Srpska “Dr Vaso Butozan” Banja Luka , Branka Radićevića 18 , Banja Luka , Bosnia and Herzegovina
2. 3 University of Belgrade, Faculty of Veterinary Medicine , Department for Economics and Statistiscs , Bulevar Oslobodenja 18 , Belgrade , Republic of Serbia
3. 4 University of Sarajevo, Faculty of Veterinary Medicine , Department for Pathobiology and Epidemiology , Zmaja od Bosne 90 , Sarajevo , Bosnia and Herzegovina .
4. 2 University of Belgrade, Faculty of Veterinary Medicine , Department of Infectious Animal Diseases and Diseases of Bees , Bulevar Oslobodenja 18 , Belgrade , Republic of Serbia