@article {1277,
	title = {Diagnostic indicators of elevated nitrogen deposition},
	volume = {144},
	year = {2006},
	author = {Pitcairn, C.E.R. and Fowler D. and Leith, I.D. and Sheppard, L.J. and Tang, Y.S. and Sutton, M.A. and Famulari D.}
}
