@misc{indiciaea2c73bd8739c,
  title = {Two new organic reference materials for δ13C and δ15N measurements and a new value for the δ13C of NBS 22 oil},
  author = {Haiping Qi and Tyler B. Coplen and Heike Geilmann and Willi A. Brand and J.K. Böhlke},
  year = {2003},
  doi = {10.1002/rcm.1219},
  url = {https://pubs.usgs.gov/publication/70185128},
  note = {Source identifier: 70185128}
}