@article {1610, title = {Biomonitoring methods for assessing the impacts of nitrogen pollution: refinement and testing}, year = {2005}, institution = {JNCC}, issn = {386}, author = {Leith, I. and van Dijk, N. and Pitcairn, C.E.R. and Wolseley, P.A. and Whitfield, C.P. and Sutton, M.A.} } @article {253, title = {Bioindicator and biomonitoring methods for assessing the effects of atmospheric nitrogen on statutory nature conservation sites}, year = {2004}, address = {Peterborough}, author = {Sutton, M.A. and Pitcairn, C.E.R. and Leith, I.D. and van Dijk, N. and Tang, Y.S. and Skiba, U. and Smart, S. and Mitchell, R. and Wolseley, P. and James, P. and Purvis, W. and Fowler, D.}, editor = {Sutton, M.A. and Pitcairn, C.E.R. and Whitfield, C.P.} } @article {839, title = {Artificial selection and heritability of ozone resistance in two populations of P. major L.}, journal = {New Phytologist}, volume = {137}, year = {1997}, pages = {645-655}, author = {Whitfield, C.P. and Davison, A.W. and Ashenden, T.W.} }