Boulygina, Eugenia, et al., (2020). "Mitochondrial and Y-chromosome diversity of the prehistoric Koban culture of the North Caucasus", in: Journal of Archaeological Science: Reports, Volume 31, June 2020, 102357, Introduction: "[T]he Koban culture was widespread on both sides of the Great Caucasus Range during the 13th/12th – 4th centuries BC. It is widely known because of its advanced metallurgy as well as developed terraced agriculture (Korobov and Borisov, 2013)."