@misc{L-80a,
  author = {P. L{\"o}nnberg},
  title = {Modifications to the operational analysis suite},
  year = {1980},
  journal = {ECMWF Technical Memoranda},
  number = {15},
  pages = {20},
  month = {1980},
  publisher = {ECMWF},
  address = {Shinfield Park, Reading},
  url = {https://www.ecmwf.int/node/10874},
  doi = {10.21957/pe8ajna9},
  language = {eng},
}