@article {1322,
	title = { Empirical nitrogen critical loads for natural and semi-natural ecosystems},
	year = {1996},
	pages = {71-96. },
	institution = {Umweltbundesamt},
	address = {Berlin},
	author = {Bobbink, R. and Hornung, M. and Roelofs, J.G.M.}
}
