@misc{indiciaeef4dbe2bcd9b,
  title = {Climate controls on C3 vs. C4 productivity in North American grasslands from carbon isotope composition of soil organic matter},
  author = {J.C. von Fischer and L.L. Tieszen and D. S. Schimel},
  year = {2008},
  doi = {10.1111/j.1365-2486.2008.01552.x},
  url = {https://pubs.usgs.gov/publication/70031896},
  note = {Source identifier: 70031896}
}