@article {598,
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	volume = {108},
	year = {1998},
	pages = {201-213},
	author = {Hallbdcken, L. and Zhang, L.Q.}
}
@article {599,
	title = {Effects of simulated nitrogen rich and acid rain on the nitrogen-fixing lichen Peltigera aphthosa (L.) Willd. },
	volume = {120},
	year = {1992},
	pages = {99-103},
	author = {Hallbdcken, L. and Kellner, O.}
}
