@article {30850,
	title = {Field studies of pine, spruce and aspen periodically subjected to sulphur gas emissions},
	volume = {8},
	year = {1977},
	pages = {105-129},
	publisher = {Water, Air, \& Soil Pollution},
	url = {http://www.springerlink.com/content/w64163m513763g38/},
	author = {Legge, A. H. and Jaques, D. R. and Amundson, R. G. and Walker, R. B.}
}
