Kis, Éva, Ferenc Schweitzer, László Palcsu, István Futó, János Balogh, and Di GlériaMária. 2012. “Investigations of Paleogeographic Variations on the Basis of the Stratotype Section of Viatovo at the Lower Danube”. Hungarian Geographical Bulletin 61 (2), 93-111. https://ojs3.mtak.hu/index.php/hungeobull/article/view/2996.