Didar Zowghi Ava Bargi Software versus IT Service: A Comparative Study from Requirements Engineering Perspective. 31-35 2011 DEXA Workshops http://doi.ieeecomputersociety.org/10.1109/DEXA.2011.76 conf/dexaw/2011 db/conf/dexaw/dexaw2011.html#ZowghiB11