@misc{indiciaec1f98529e128,
  title = {13CO2/12CO2 isotopic ratio measurements using a difference frequency-based sensor operating at 4.35 micrometers},
  author = {Erdelyi, M. and Richter, D. and Tittel, F. K.},
  year = {2002},
  url = {https://ntrs.nasa.gov/citations/20040087818},
  note = {Source identifier: 20040087818}
}