APA   Click to copy
Ricklefs, R. E., & Marquis, R. J. (2012). Species richness and niche space for temperate and tropical folivores. Oecologia, 168, 213–220.

Chicago/Turabian   Click to copy
Ricklefs, Robert E, and Robert J Marquis. “Species Richness and Niche Space for Temperate and Tropical Folivores.” Oecologia 168 (2012): 213–220.

MLA   Click to copy
Ricklefs, Robert E., and Robert J. Marquis. “Species Richness and Niche Space for Temperate and Tropical Folivores.” Oecologia, vol. 168, Springer, 2012, pp. 213–20.

@article{ricklefs2012a,
  title = {Species richness and niche space for temperate and tropical folivores},
  year = {2012},
  journal = {Oecologia},
  pages = {213--220},
  publisher = {Springer},
  volume = {168},
  author = {Ricklefs, Robert E and Marquis, Robert J}
}