Ėkonomičeskie svjazi antičnych gorodov severnogo Pričernomor'ja s plenenami Pridneprov'ja i Pobuž'ja v IV - II vv. do n.ė. (Russ.m.engl.Res.) The economic ties of the North Black Sea cities with the tribes of the Dnepr and Bug regions in the fourth to second centuries B.C. - Onajko, N.A (1970)