@misc{mehrtens_particle_properties_1997, 
author={Mehrtens, H.,Reichardt, J.},
title={Particle properties of PSC observed on January 19, 1997 above Andoya and Esrange},
year={1997},
howpublished = {conference lecture: Schliersee (D); September 22-26, 1997},
note = {Online available at: \url{} (DOI). Mehrtens, H.; Reichardt, J.: Particle properties of PSC observed on January 19, 1997 above Andoya and Esrange. 4th European Symposium on Polar Stratospheric Ozone. Schliersee (D), 1997.}}