@article{242193,
      url = {http://digitallibrary.un.org/record/242193},
      title = {Methods used to calculate national emissions of nitrogen  oxides : note /},
      publisher = {UN,},
      recid = {242193},
      pages = {5 p. :},
      address = {Geneva :. 1987-07-10},
      year = {1987},
      month = {Jul},
}