Hammond, Nicholas Geoffrey Lemprière. Epirus: the Geography, the Ancient Remains, the History and Topography of Epirus and Adjacent Areas. Oxford: Clarendon Press, 89–90. o. (1967). ISBN 9780198142539 "The greater part of the canton of Filiates lies north of the lower Kalamas. It is contained between the river and its northern watershed, along which the present frontier runs between Greece and Albania. There is little fertile land except in the delta and the inner basin of the Kalamas. The northern part of the canton is broken up by a tangle of mountain peaks, and i found it difficult to traverse.... In contrast to the Albanian-speaking villages of the Kalamas delta and basin, these villages are Greek in speech and outlook, … The other villages have on average some 200 houses, and they are considerably larger than the scattered Albanian-speaking villages of the Kalamas basin."
Strabo. Geography, 7.7. Note #35: "The Thyamus, or Thyamis, is now called Glycys, and the Acheron, Calamas."
Pausanias. Description of Greece, Attica, 1.11.2. "Helenus on his death passed on the kingdom to Molossus, son of Pyrrhus, so that Cestrinus with volunteers from the Epeirots took possession of the region beyond the river Thyamis, while Pergamus crossed into Asia and killed Areius…"
