%0 Report %D 2005 %T Biomonitoring methods for assessing the impacts of nitrogen pollution: refinement and testing %A Leith, I. %A van Dijk, N. %A Pitcairn, C.E.R. %A Wolseley, P.A. %A Whitfield, C.P. %A Sutton, M.A. %B JNCC %I JNCC %G eng