"Ancient Krasnyi Yar". American Museum of Natural History. Retrieved 10 October 2012.
doi.org
Outram, Alan K., Natalie A. Stear, Robin Bendrey, Sandra Olsen, Alexei Kasparov, Victor Zailbert, Nick Thorpe, and Richard P. Evershed, 2009 "The Earliest Horse Harnessing and Milking," Science 323: 1332-1335 doi:10.1126/science.1168594
