@article {1339,
	title = {The effects of air-borne ammonium sulphate on Pinus nigra in the Netherlands},
	journal = {Plant Soil},
	volume = {42},
	year = {1985},
	pages = {372{\textendash}377},
	author = {Roelofs, J.G.M. and Kempers, A.J. and Houdijk, A.L.F.M. and Jansen, J.}
}
