@inproceedingsDücker_Geiger_Lehrenfeld_Müller_Tahedl_1997, place=Capri, Italy, title=A Visual Programming Language for Qualitative Data, DOI=10.1109/VL.1997.626593, booktitle=Proceedings of the 1997 IEEE Symposium on Visual Languages, author=Dücker, M. and Geiger, Christian and Lehrenfeld, Georg and Müller, Wolfgang and Tahedl, C., year=1997