@article{181713,
      note = {At head of title: Earthwatch, Global Environment  Monitoring System.},
      url = {http://digitallibrary.un.org/record/181713},
      title = {Urban air pollution in megacities of the world.},
      publisher = {WHO :},
      recid = {181713},
      pages = {viii, 230 p. :},
      address = {Oxford (United Kingdom) :. 1992},
      year = {1992},
}