@misc{indiciae8497fa675e6c,
  title = {Direct measurement of surface carbon concentrations},
  author = {Filleux, C. and Tombrello, T. A. and Burnett, D. S.},
  year = {1977},
  url = {https://ntrs.nasa.gov/citations/19780057857},
  note = {Source identifier: 19780057857}
}