Norbert Siegmund Marko Rosenmüller Martin Kuhlemann Christian Kästner Gunter Saake Measuring Non-Functional Properties in Software Product Line for Product Derivation. 187-194 2008 APSEC http://dx.doi.org/10.1109/APSEC.2008.45 conf/apsec/2008 db/conf/apsec/apsec2008.html#SiegmundRKKS08