@article {129,
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	volume = {6},
	number = {s 1},
	year = {2000},
	pages = {19-34},
	isbn = {1354-1013},
	author = {Walker, DA}
}
@article {117,
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	journal = {Global Change Biology},
	volume = {12},
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	year = {2006},
	pages = {42-55},
	isbn = {1365-2486},
	author = {Jia, G.J. and Epstein, H.E. and Walker, DA}
}
