@article{11216,
  author = {Mats Larson and Axel M{\r a}lqvist},
  title = {A Posteriori Error Estimates for Mixed Finite Element Approximations of Elliptic Problems},
  year = {2008},
  journal = {Numerische Mathematik},
  volume = {108},
  pages = {487-500},
  publisher = {Springer},
  note = {DOI 10.2007/s00211-007-0121-y},
}