Maintenance work on the ZORA database servers is scheduled for Thursday 25th July 2019 from 19:00-20:00. During this period ZORA and JDB will not be available. Thank you for your understanding.
Weibel, Robert; Brassel, Kurt (2006). Map generalization – what a difference two decades make. In: Fisher, Peter. Classics from IJGIS: Twenty years of the International Journal of Geographical Information Science and Systems. London (UK): Taylor & Francis, 59-65.