A further argument against a proto-Albanian affinity of the Koman culture is that very similar material is found in central Dalmatia, Montenegro, western Macedonia and south-eastern Bulgaria, along the Via Egnatia; and even islands such as Corfu and Sardinia. The "late Roman" character of the assemblages has led some to hypothesize that it represented Byzantine garrisons. However, already by this time, literary sources give testimony of widespread Slavic settlements in the central Balkans. Specifically for Albania, the study of lexicon and toponyms might suggest that speakers of proto-Albanian, Slavic and Romance co-existed but occupied specific ecologic/ economic niches.