Complex sentence: Grievances mainly related to the expulsion of Montenegrin people from the Kosovo region and Vojvodina, as well as the influx of refugees from other parts of Yugoslavia and those fleeing the Ustaše terror in the regions along the borders with Bosnia and Herzegovina.
Split into simpler sentences: Grievances mainly related to the expulsion of Montenegrin people from the Kosovo region and Vojvodina, as well as the influx of refugees from other parts of Yugoslavia. Other refugees were fleeing the terror of the Ustaše in the regions along the borders with Bosnia and Herzegovina.