Risto Hillamo, Maija-Riitta Hirvonen, Tarja Koskentalo, Markus Sillanpää, Arto S. Pennanen, Arja I. Hälinen, Päivi Aarnio, Paul Borm, Raimo O. Salonen, Tingming Shi, Erik Sandell,
Chemical and in vitro toxicologic characterization of wintertime and springtime urban-air particles with an aerodynamic diameter below 10 microm in Helsinki. Scandinavian Journal of Work, Environment & Health. ,vol. 30, pp. 80- 90 ,(2004)