@Misc{ 
  spe10,
  author = { Spector, Daniel },
  title = { Simple proofs of some results of Reshetnyak },
  journal = { Proc. Amer. Math. Soc. },
  year = { 2010 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/505/ },
  note = { cvgmt preprint}
}