@article{93859,
      url = {http://digitallibrary.un.org/record/93859},
      title = {Questionnaire regarding statistics of ecological  freshwater quality.},
      publisher = {UN,},
      recid = {93859},
      pages = {10 p.},
      address = {Geneva :. 1990-01-16},
      year = {1990},
      month = {Jan},
}