Original sentence: Following the Dayton Agreement of 1995, Republika Srpska achieved international recognition as an entity within Bosnia and Herzegovina.Its largest city and administrative centre is Banja Luka, lying on the Vrbas river.The war saw the expulsion of the vast majority of Croats and Bosniaks from the territory claimed by Republika Srpska and an inflow of Serbs expelled from Federation of Bosnia and Herzegovina
Edited sentence: Administrative centre is in Banja Luka, lying on the Vrbas river.The war saw the expulsion of the vast majority of Croats and Bosniaks from the territory claimed by Republika Srpska and an inflow of Serbs left  Federation of Bosnia and Herzegovina voluntary