@manual{76618,
  author = {C. Temperton},
  title = {Direct methods for the solution of the discrete Poisson equation: Some comparisons},
  year = {1977},
  number = {13},
  pages = {23},
  month = {07/1977},
  publisher = {ECMWF},
  address = {Shinfield Park, Reading},
  language = {eng},
}