[3] He was a team leader in archaeological excavations along the Ibar River between 2003 and 2009, and taught general medieval studies in the Faculty of Philosophy at the University of Banja Luka.
His field of research encompassed the early medieval history of the South Slavs on the territories of Serbia, Bosnia, Croatia, Bulgaria, and Greece.
[2] He focused on the history of the Serbs during this period, but he also provided new insights on De Administrando Imperio, the work of the Byzantine emperor Constantine VII.
His main theory was that the chapters devoted to Croats and Serbs were largely based on a lost source written by Anastasius Bibliothecarius in the late 9th century, hypothetically called De conversione Croatorum et Serborum.
[1] Živković also worked on the Chronicle of the Priest of Duklja (Latin: Gesta regum Sclavorum), an early history of the Western South Slav territories and their rulers.