@phdthesis{74452,
  author = {B. Farrell and P.J. Ioannou},
  title = {Approximating optimal state estimation},
  year = {2003},
  journal = {Seminar on Recent developments in data assimilation for atmosphere and ocean, 8-12 September 2003},
  pages = {369-392},
  month = {2003},
  publisher = {ECMWF},
  address = {Shinfield Park, Reading},
  language = {eng},
}