@article{KahmenSachseArndtetal.2011,
  author    = {Ansgar Kahmen and Dirk Sachse and Stefan K. Arndt and Kevin P. Tu and Heraldo Farrington and Peter M. Vitousek and Todd E. Dawson},
  title     = {Cellulose delta O-18 is an index of leaf-to-air vapor pressure difference (VPD) in tropical plants},
  journal   = {Proceedings of the National Academy of Sciences of the United States of America},
  volume    = {108},
  number    = {5},
  pages     = {1981 -- 1986},
  doi       = {10.1073/pnas.1018906108},
  year      = {2011},
}