@article{110456,
      note = {"A United States Department of Commerce publication."},
      author = {Simmons, W. R. and Wescott, J. W., and Hall, Freeman F.,},
      url = {http://library.usi.edu/record/110456},
      title = {Acoustic echo sounding as related to air pollution in  urban environments},
      publisher = {Environmental Research Laboratories,},
      recid = {110456},
      pages = {iii, 77 p.},
      address = {Boulder, Colo.,},
      year = {1971},
}