Diverging long-term trends in ambient urban particle mass and number concentrations associated with emission changes caused by the German unification

Cyrys [Josef] ; Heinrich [Joachim] ; Heyder [Joachim] ; Kreyling [Wolfgang G.] ; Peters [Annette] ; Pitz [Mike] ; Stölzel [Matthias] ; Tuch [Thomas] ; Wichmann [H. Erich]