M. E. Koukouli, S. Kazadzis, V. Amoiridis, C. Ichoku, D. S. Balis, A. F. Bais: Signs of a negative trend in the MODIS aerosol optical depth over the Southern Balkans, Atmospheric Environment Vol 44(9) p.1219-1228 Doi: 10.1016/j.atmosenv.2009.11.024, 2010
