@Article{ 
  barfoc,
  author = { Barchiesi, Marco and Focardi, Matteo },
  title = { Homogenization of the Neumann problem in perforated domains: an alternative approach },
  journal = { Calc. Var. Partial Differential Equations },
  year = { 2011 },
  volume = { 42 },
  pages = { 257-288  },
  URL = { http://cvgmt.sns.it/paper/1224/ },
  note = { cvgmt preprint}
}