@article{44826,
  author = {Duncan Menge and Simon Levin and Lars Hedin},
  title = {Facultative versus obligate nitrogen fixation strategies and their ecosystem consequences},
  year = {2009},
  journal = {The American Naturalist},
  volume = {174},
  number = {4},
  pages = {465{\textendash}477},
  url = {http://www.jstor.org/stable/10.1086/605377},
  language = {eng},
}