First record of Dikerogammarus villosus (Amphipoda, Gammaridae) and Jaera istri (Isopoda, Asselota) from the Slovak-Hungarian part of the Danube river / Ferdinard Šporka. Biologia. Section A. Section B. Section C, Botany. Zoology. Cellular and molecular biology Roč. 54, č. 5 (1999), s. 538