@article {667,
	title = {Direct Effects of Sulphur on Forests in Europe - a Regional Model of Risk},
	year = {1987},
	publisher = {International Institute for Applied Systems Analysis},
	address = {Luxembourg},
	url = {http://webarchive.iiasa.ac.at/Admin/PUB/Documents/WP-87-057.pdf},
	author = {Makela, A. and Materna, J. and Schoop, W.}
}
