Wikipedia
Körös-ér
The Körös-ér (in Hungarian) or Kereš (in Serbian; also Cyrillic: Кереш) is a river in southern Hungary and northern Serbia, a 70 km long right tributary to the Tisa river. It flows entirely within the Bačka region of both Hungary and Serbia ( Vojvodina): 27 km in Hungary, 15 km as a border river and 27 km in Serbia.