Werner, P.C. Potsdam Institute for Climate Impact Research and Cooperation Partners;
Gerstengarbe, Friedrich-Wilhelm Potsdam Institute for Climate Impact Research;
Werner, P., Gerstengarbe, F.-W. (2003): Visual meteorological observations as indicators of climate changes, derived from long-term time series of the Potsdam station. - Meteorologische Zeitschrift, 12, 1, 47-50.