@article{101978,
      url = {http://digitallibrary.un.org/record/101978},
      title = {International classification of coal /},
      publisher = {UN,},
      recid = {101978},
      pages = {11, 3 p. :},
      address = {Geneva :. 1983-08-01},
      year = {1983},
      month = {Aug},
}