Author(s):
1. Danijela Vuković, Elektrotehnički fakultet Univerziteta u Banjoj Luci, Republic of Srpska, Bosnia and Herzegovina
2. Duško Dudić, Department of Chemistry, University of the Free State, Private Bag X13, Phuthaditjhaba, 9866 South A, Serbia
3. Blanka Škipina, Faculty of Technology Banja Luka, Republic of Srpska, Bosnia and Herzegovina
4. Petar Matavulj, Elektrotehnički fakultet, Univerzitet u Beogradu, Bulevar Kralja Aleksandra 73, Serbia