@article {707,
	title = {Responses of Norwegian alpine Betula nana community to nitrogen fertilization},
	journal = {Canadian Journal of Botany },
	volume = {75},
	year = {1997},
	pages = {108-120},
	author = {Paal, J. and Fremstad, E. and Mols, T.}
}
@proceedings {222,
	title = {Nitrogen eutrophication and critical load for nitrogen based upon changes in flora and fauna in (semi)-natural terrestrial ecosystems},
	year = {1993},
	pages = {pp. 111-159},
	publisher = {Nordic Council of Ministers, Copenhagen, Denmark},
	address = {L{\"o}keberg, Sweden},
	author = {Bobbink, R. and Boxman, D. and Fremstad, E. and Heil, G. and Houdijk, A. and Roelofs, J.}
}
