@article { JJS14, title = {Geo-Temporal Visual Analysis of Customer Feedback Data Based on Self-Organizing Sentiment Maps}, journal = {International Journal On Advances in Intelligent Systems}, number = {1 and 2}, pages = {237--246}, year = {2014}, author = {Janetzko, Halldor and J├Ąckle, Dominik and Schreck, Tobias} }