@article{metrics09,
  author    = {Luca de Alfaro and
               Marco Faella and
               Mari{\"e}lle Stoelinga},
  title     = {Linear and Branching System Metrics},
  journal   = {IEEE Trans. Software Eng.},
  volume    = {35},
  number    = {2},
  year      = {2009},
  pages     = {258-273}
}