@article{10591,
  author = {John Krogstie and Arthur Jahr and Dag Sj{\o}berg},
  title = {A Longitudinal Study of General and Functional Maintenance in Norway},
  year = {2006},
  journal = {Information and Software Technology},
  volume = {48},
  number = {11},
  pages = {993-1005},
  month = {November},
}