TY - Generic T1 - Nitrogen eutrophication and critical load for nitrogen based upon changes in flora and fauna in (semi)-natural terrestrial ecosystems Y1 - 1993 A1 - Bobbink, R. A1 - Boxman, D. A1 - Fremstad, E. A1 - Heil, G. A1 - Houdijk, A. A1 - Roelofs, J. T3 - Critical loads for nitrogen. Proceedings of a UN-ECE workshop at Lökeberg, Sweden, 6-10 April 1992 PB - Nordic Council of Ministers, Copenhagen, Denmark CY - Lökeberg, Sweden ER -