@Article{ 
  delmul,
  author = { De Lellis, Camillo and Müller, Stefan },
  title = { Sharp rigidity estimates for nearly umbilical surfaces },
  journal = { Journal of Differential Geometry },
  year = { 2003 },
  volume = { 69 },
  number = { 75--110 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1306/ },
  note = { cvgmt preprint}
}