@misc{indiciaebdc4f061dcd8,
  title = {Extractable organic matter in Precambrian cherts},
  author = {Kaplan, I. R. and Schopf, J. W. and Smith, J. W.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19710008247},
  note = {Source identifier: 19710008247}
}