@article{100698,
      url = {http://digitallibrary.un.org/record/100698},
      title = {Preparation of an industrial classification of medium-rank  coals /},
      publisher = {UN,},
      recid = {100698},
      pages = {7 p. :},
      address = {Geneva :. 1982-07-08},
      year = {1982},
      month = {Jul},
}