1. Allen, A.G., 1988, A physico-chemical investigation of atmospheric sulphur, nitrogen and chlorine compounds, Ph.D. Thesis, University of Essex.
2. Appel B.R., Cheng W. and Salaymeh F., 1989, Sampling of carbonaceous particles in the atmosphere,Atmos. Environ. 23, 2167–2175.
3. ApSimon H.M., Kruse M. and Bell J.M.B., 1987, Ammonia emissions and their role in acid deposition,Atmos. Environ. 21, 1939–1946.
4. Asman W.A.H., Drukker B. and Janssen A.J., 1988, Modelled historical concentrations and depositions of ammonia and ammonium in Europe,Atmos. Environ. 22, 725–735.
5. Campbell G.W., Cocksedge J.L. and 7 other authors, 1988, Acid rain in the United Kingdom: spatial distributions and seasonal variations in 1986, Report No. LR 691, Warren Spring Laboratory, Stevenage.