@inbook {2007,
	title = {Zinc Phytotoxicity},
	booktitle = {In A. D. Robson Proceedings of the International Symposium on Zinc in Soil and Plants},
	year = {1993},
	pages = {135-150},
	publisher = {Kluwer},
	organization = {Kluwer},
	address = {University of Western Australia},
	author = {Chaney, R. L}
}
@article {227,
	title = {Zeigerwerte von Pflanzen in Mitteleuropa},
	journal = {Scripta Geobotanica},
	volume = {18},
	year = {1991},
	pages = {1-248},
	author = {Ellenberg, H. and Weber, H.E. and Dull, R. and Wirth, V. and Werner, W. and Pauli{\ss}en, D.}
}
