Wilhelm A.: Growth of the mudminnow (Umbra krameri Walbaum) in river Ér. In: Tiscia 34. pp. 57-60. (2003)
Wilhelm A.: Spawning of the European mudminnow (Umbra krameri Walbaum) in the basin of the river Ér. In: Tiscia 31. pp. 55-58. (1998)