H. Janetzko, D. Jäckle and T. Schreck.
Geo-Temporal Visual Analysis of Customer Feedback Data Based on Self-Organizing Sentiment Maps.
International Journal On Advances in Intelligent Systems, International Academy, Research, and Industry Association (IARIA), 7(1 and 2):237--246, 2014.

H. Janetzko, D. Jäckle and T. Schreck.
Comparative visual analysis of large customer feedback based on self-organizing sentiment maps.
Proc. International Conference on Advances in Information Mining and Management, 12-17, Best Paper Award, 2013.

M. C. Hao, C. Rohrdantz, H. Janetzko, D. A. Keim, U. Dayal, L.-E. Haug, M. Hsu and F. Stoffel.
Visual sentiment analysis of customer feedback streams using geo-temporal term associations.
Information Visualization, SAGE Publications, 12(3-4):273-290, DOI: 10.1177/1473871613481691, 2013.

M. C. Hao, C. Rohrdantz, H. Janetzko, D. A. Keim, U. Dayal, L.-E. Haug and M. Hsu.
Integrating Sentiment Analysis and Term Associations with Geo-Temporal Visualizations on Customer Feedback Streams.
SPIE 2012 Conference on Visualization and Data Analysis (VDA 2012), Best Paper Award, DOI: http://dx.doi.org/10.1117/12.912202, 2012.