@article{rené_ault_frushour_1994, 
  title={Electromagnetic and Gravimetric Mapping of a Partly Collapsed Underground Limestone Mine in Clark County, IN}, 
  volume={1994}, 
  DOI={10.21000/jasmr94040376}, 
  publisher={American Society of Mining and Reclamation (ASMR)}, 
  author={René and Ault and Frushour}, 
  year={1994}
  }