@article{184685,
      note = {Distributed to depository libraries in microfiche.},
      author = {Strickland, W. H. and King, Robert H.},
      url = {http://library.usi.edu/record/184685},
      title = {Characteristics of ultrasonic ranging sensors in an  underground environment [microform] /},
      publisher = {U.S. Dept. of the Interior, Bureau of Mines,},
      recid = {184685},
      pages = {ii, 39 p. :},
      address = {Washington, D.C. :},
      year = {1993},
}