@article{472946,
      recid = {472946},
      title = {Protecting visibility in national parks and wilderness  areas [electronic resource] /},
      publisher = {National Academy Press,},
      address = {Washington, D.C. :},
      pages = {xv, 446 p. :},
      year = {1993},
      url = {http://library.usi.edu/record/472946},
}