Debevec, Ed, and Mark S. Udevitz. "Sightmod." Alaska Science Center, USGS, n.d.
Minna Pekkonen, Tarmo Ketola, Jouni T. Laakso. Resource Availability and Competition Shape the Evolution of Survival and Growth Ability in a Bacterial Community. 30 September 2013. Document. 19 January 2018. <http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0076471>.
Sanderson, Eric W. "How Many Animals Do We Want to Save? The Many Ways of Setting Population Target Levels for Conservation." BioScience, vol. 56, no. 11, Nov. 2006, pp. 911–22.