@misc{indiciae33dbcbd4c37c,
  title = {Principal facts for gravity stations in the Newark-Gettysburg Triassic Basin, Pennsylvania and adjacent states},
  author = {John R. Sumner and R. F. Meyer and J.M. Dunleavy and R.S. Fleming},
  year = {1976},
  doi = {10.3133/ofr76302},
  url = {https://pubs.usgs.gov/publication/ofr76302},
  note = {Source identifier: ofr76302}
}