Glossary of Ecology (6th ed.) by Krebs (2009)
- occurs when a number of organisms of the same or different species utilize common resources that are in short supply (exploitation) or when the organisms harm one another in the process of acquiring these resources (interference).
Glossary of "Evolution (4th ed.)" by Futuyma & Kirkpatrick (2017)
- An interaction between individuals of the same species or different species whereby resources used by one are made unavailable to others.
- Krebs, C. J. 2009. Ecology, 6th ed. -xvi + 655 pp. Pearson Benjamin Cummings, San Francisco.
- Futuyma, D. J. & Kirkpatrick, M. 2017. Evolution, 4th ed. -xviii + 602 pp. Sinauer Associates, Inc., Sunderland.