@article{44806,
  author = {Duncan Menge and Simon Levin and Lars Hedin},
  title = {Evolutionary tradeoffs can select against nitrogen fixation and thereby maintain nitrogen limitation},
  year = {2008},
  journal = {Proceedings of the National Academy of Sciences},
  volume = {105},
  number = {5},
  pages = {1573{\textendash}1578},
  url = {http://www.pnas.org/content/105/5/1573.short},
  language = {eng},
}