TY - GEN A1 - Wiegleb, Gerhard A1 - Brux, Holger A1 - Herr, W. T1 - Human impact on the ecological performance of Potamogeton species in northwestern Germany T2 - Vegetatio Y1 - 1991 SN - 0042-3106 VL - 97 IS - 2 SP - 161 EP - 172 ER -