Lianou M, Chalbot M.C., Kavouras I.G, Kotronarou A, Karakatsani A, Katsouyanni K, Puustinnen A, Hameri K, Vallius M, Pekkanen J, Meddings C, Harrison R.M, Ayres J.G, Brick H ten, Kos G, Meliefste K, Hartog J de, Hoek G.: Temporal variations of atmospheric aerosol in four European urban areas, Environmental Science and Pollution Research Vol 18(7) p.1202-1212 Doi: 10.1007/s11356-011-0471-y, 2011