@book{ Solr-126825, title = {Precipitation chemistry in the United States vol 0001: summary of ion concentration variability 1979 - 1984 : Analysis of interegional project IR-7 deposition chemistry data.}, series = {WRI continuum ;}, author = {Knapp, W. W.}, editor = {Knapp, W. W.}, address = {Washington, DC}, publisher = {World Resources Institute}, year = {1988}, note = {englisch}, }