@article{HoefnerKhedriMoeller2011,
  author    = {Peter H{\"o}fner and Ridha Khedri and Bernhard M{\"o}ller},
  title     = {An algebra of product families},
  journal   = {Software und Systems Modeling},
  volume    = {10},
  number    = {2},
  pages     = {161 -- 182},
  doi       = {10.1007/s10270-009-0127-2},
  year      = {2011},
}