Serena Bianchetti, Michele Cataudella, Hans-Joachim Gehrke, [Brill's Companion to Ancient Geography: The Inhabited World in Greek and Roman Tradition (BRILL, 4 Dec 2015) p 263.
doi.org
Tønnes Bekker-Nielsen, Marit Jensen, "Two Pontic Rivers", Cedrus: The Journal of MCRI3:231-2142 (2015), doi:10.13113/CEDRUS.2015011411