APA   Click to copy
Clapp, J., Desmarais, A., & Margulis, M. (2015). State of the world food system.

Chicago/Turabian   Click to copy
Clapp, J., A. Desmarais, and M. Margulis. “State of the World Food System” (2015).

MLA   Click to copy
Clapp, J., et al. State of the World Food System. 2015.

@article{j2015a,
  title = {State of the world food system},
  year = {2015},
  author = {Clapp, J. and Desmarais, A. and Margulis, M.}
}