@article{6856,
      recid = {6856},
      author = {Rock, Robert L.},
      title = {Evaluation of radioactive aerosols in United States  underground coal mines /},
      publisher = {U.S. Dept. of the Interior, Mining Enforcement and Safety  Administration,},
      address = {Washington :},
      pages = {10 p. :},
      year = {1975},
      url = {http://library.usi.edu/record/6856},
}