"A Dictionary of Ecology, Evolution and Systematics (2nd ed.)" by Lincoln et al. (1998)
- A derived SI unit of energy and work, defined as the work done to displace a point, by the application of a force of 1 newton, through a distance of 1 metre in the direction of the force; also the work done when a current of 1 ampere flows through a resistance of 1 ohm for 1 second; see Appendix 16.
- Lincoln, R., Boxshall, G. & Clark, P. 1998. A Dictionary of Ecology, Evolution and Systematics. ix + 361 pp. Cambridge University Press, Cambridge.