From 1912-1913, Kobasica published the "Srpski Glas", the organ of the Serb People's Radical Party in Croatia and Slavonia. He was also the author of three monographs entitled "Srpsko-Bugarski Rat", "The Serbo-Bulgarian War", Sarajevo, 1913, "Finale", and "Stjepan Radić za vrijeme aneksione krize i svjetskoga rata" "Stjepan Radić at the Time of the Annexation Crisis and the World War" (1924).