@misc{76744,
  author = {Y. Trémolet},
  title = {Diagnostics of linear and incremental approximations in 4D-Var},
  year = {2003},
  journal = {ECMWF Technical Memoranda},
  number = {399},
  pages = {16},
  month = {02/2003},
  publisher = {ECMWF},
  address = {Shinfield Park, Reading},
  url = {https://www.ecmwf.int/node/12814},
  doi = {10.21957/ndvw66a0},
  language = {eng},
}