%0 Report %D 2007 %T Report on the Workshop on Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts %A UNECE %B Review of the 1999 Gothenburg Protocol %I United Nations Economic and Social Council (UNECE), Executive body for the Convention of Long-Range Transboundary Air pollution: Working Group on Strategies and Review %C Geneva %8 04/2007 %U http://www.ammonia-ws.ceh.ac.uk/documents/ece_eb_air_wg_5_2007_3_e.pdf %N Thirty-ninth session %F critical load level reference