@article{CTT100813494,
  author = {Ostrom N. E. and Gandhi H. and Coplen T. B. and Toyoda S. and Böhlke J. K. and Brand W. A. and Casciotti K. L. and Dyckmans J. and Giesemann A. and Mohn J. and Well R. and Yu L. and Yoshida N.},
  title = {Preliminary assessment of stable nitrogen and oxygen isotopic composition of USGS51 and USGS52 nitrous oxide reference gases and perspectives on calibration needs.},
  journal = {Rapid Commun. Mass Spectrom.},
  year = 2018,
}

@article{CTT100766913,
  author = {Nathaniel E. Ostrom and Hasand Gandhi and Tyler B. Coplen and Sakae Toyoda and J.K. Boehlke and Wili A. Brand and Karen L. Casciotti and Jens Dyckmans and Anette Giesemann and Joachim Mohn and Reinhard Well and Longfei Yu and Naohiro Yoshida},
  title = {Preliminary assessment of stable nitrogen and oxygen isotopic composition of USGS51 and USGS52 nitrous oxide reference gases and perspectives on calibration needsJournal: Rapid Communications in Mass Spectrometry},
  journal = {Rapid Commun. Mass Spectrom.},
  year = 2018,
}