@misc{indiciaecb6ce51005f5,
  title = {Instrumentation studies of earth tremors related to geology and to mining at the Somerset coal mine, Colorado},
  author = {Frank W. Osterwald and C.R. Dunrud and J.B. Bennetti and J. O. Maberry},
  year = {1972},
  doi = {10.3133/pp762},
  url = {https://pubs.usgs.gov/publication/pp762},
  note = {Source identifier: pp762}
}