@book{
  international1971iaea,
  title={Nitrogen-15 in Soil–plant Studies},
  series={Panel Proceedings Series},
  year={1971},
  isbn={92-0-111171-1},
  url={https://www.iaea.org/publications/3016/nitrogen-15-in-soil-plant-studies},
  publisher={INTERNATIONAL ATOMIC ENERGY AGENCY},
  address={Vienna}
}