TY - RPRT T1 - Empirical nitrogen critical loads: update since Lokeberg (1992) Y1 - 1995 A1 - Bobbink, R. A1 - Roelofs, J.G.M. ED - Hornung, M. ED - Sutton, M.A. ED - Wilson, R.B. JF - Mapping and modelling of critical loads for nitrogen - a workshop report PB - Institute of Terrestrial Ecology CY - Bush ER -