@article {1462, title = {Base cation depletion, eutrophication and acidification of species-rich grasslands in response to long-term simulated nitrogen deposition.}, journal = {Environmental Pollution}, volume = {155}, year = {2008}, pages = {336-349}, author = {Horswill, P. and O{\textquoteright}Sullivan, O. and Phoenix, G.K. and Lee, J.A. and Leake, J.R.} } @mastersthesis {1106, title = {Long term nitrogen pollution impacts on grasslands and their recovery responses}, year = {2008}, school = {University of Sheffield}, address = {Sheffield}, author = {O{\textquoteright}Sullivan, O.} }