@book{MaChen2004,
  author    = {Ma, Li and Chen, Dezhong},
  title     = {Curve Shotening in a Riemannian Manifold},
  series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell},
  journal   = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell},
  publisher = {Univ.},
  address   = {Potsdam},
  issn      = {1437-739X},
  pages     = {20 S.},
  year      = {2004},
  language  = {en}
}
@book{DuMa2001,
  author    = {Du, Yihong and Ma, Li},
  title     = {Some remarks related to de Giorgi{\"i}s Conjecture},
  series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell},
  journal   = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell},
  publisher = {Univ.},
  address   = {Potsdam},
  issn      = {1437-739X},
  pages     = {8 S.},
  year      = {2001},
  language  = {en}
}