@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)} }