@article {1649,
	title = {The yield of winter cereals exposed to sulphur dioxide under field conditions.},
	journal = {Agriculture, Ecosystems and Environment},
	volume = {33},
	year = {1991},
	pages = {193-213},
	author = {McLeod, A.R. and Roberts, T.M. and Alexander, K. and Cribb, D.M.}
}
@article {1651,
	title = {Yield Responses of Different Crop Species to Long-Term Fumigation with Sulphur Dioxide in Open-Top Chambers},
	journal = {Environmental Pollution},
	volume = {67},
	year = {1990},
	pages = {15-28},
	author = {Weigel, H.J. and Adaros, G. and Jager, H.J.}
}
