00610cam|a2200157 i 450000500170000000800410001702000150005803500150007324502080008826000360029630000110033265000210034365000230036470000210038771000440040820260817171456.0040831s1979    enk     r    0000|0 eng d  a0080234429  a.b1011544400aBiological aspects of freshwater pollution :bproceedings of the Course held at the Joint Research Centre of the Commission of the European Communities, Ispra, Italy, 5-9 June 1978 /cedited by O. Ravera  aOxford :bPergamon Press,c1979  a214 p. 0aWaterxPollution 0aFreshwater ecology1 aRavera, O.,eed.2 aCommissions of the European Communities