@article{155002,
      author = {Berggren, Dwain.},
      url = {http://library.usi.edu/record/155002},
      title = {Measuring coal seam thicknesses with normal-lateral  electric logs /},
      publisher = {Illinois State Geological Survey,},
      recid = {155002},
      pages = {iv, 26 p. :},
      address = {Champaign, Ill. :},
      year = {1991},
}