Complex sentence: Albanians have been registered in the modern Bulgarian capital Sofia since the early 17th century; other possible colonies south of the Balkan Mountains included Gorno Arbanasi and Dolno Arbanasi near Asenovgrad.
Split into simpler sentences: Albanians have been registered in the modern Bulgarian capital Sofia since the early 17th century. Other possible colonies south of the Balkan Mountains included Gorno Arbanasi and Dolno Arbanasi near Asenovgrad.