@article {1329, title = {Natural vegetation responses to atmospheric nitrogen deposition - critical levels and loads of nitrogen for vegetation growing on contrasting native soils}, year = {1997}, institution = {University of Sheneld}, address = {Sheneld}, author = {Carroll, J.A. and Caporn, S.J.M. and Morecrof, M.D. and Lee, J.A. and Johnson, D. and Taylor, A. and Leake, J.R. and Campbell, C.D. and Cawley, L. and Lei, Y. and Read, D.J.} } @inbook {527, title = {Acid Rain and its Impact: The Critical Loads Debate}, year = {1994}, pages = {146-150}, publisher = {Environmental Change Research Centre/ENSIS}, organization = {Environmental Change Research Centre/ENSIS}, chapter = {Critical loads of nitrogen for upland heather (Calluna vulgaris). }, address = {London}, author = {Caporn, S.J.M and Carroll, J. and Lei, Y. and Song, W. and Read, D.J. and Lee, J.A. and Battarbee, R.W. (Eds)} }