Britannica Online. «Lake (physical feature)». Consultado el 25 de junio de 2008. «[a Lake is] any relatively large body of slowly moving or standing water that occupies an inland basin of appreciable size. Definitions that precisely distinguish lakes, ponds, swamps, and even rivers and other bodies of nonoceanic water are not established. It may be said, however, that rivers and streams are relatively fast moving; marshes and swamps contain relatively large quantities of grasses, trees, or shrubs; and ponds are relatively small in comparison to lakes. Geologically defined, lakes are temporary bodies of water.»
calacademy.org
«Definition of Life». California Academy of Sciences. 2006. Archivado desde el original el 8 de febrero de 2007. Consultado el 7 de enero de 2007.
Johnson, D. L.; Ambrose, S. H.; Bassett, T. J.; Bowen, M. L.; Crummey, D. E.; Isaacson, J. S.; Johnson, D. «Meanings of Environmental Terms». Journal of Environmental Quality26 (3): 581-589. ISSN0047-2425. doi:10.2134/jeq1997.00472425002600030002x.
Johnson, D. L.; Ambrose, S. H.; Bassett, T. J.; Bowen, M. L.; Crummey, D. E.; Isaacson, J. S.; Johnson, D. N.; Lamb, P. et al. (1997). «Meanings of Environmental Terms». Journal of Environmental Quality26 (3): 581-589. doi:10.2134/jeq1997.00472425002600030002x.Se sugiere usar |número-autores= (ayuda)
Johnson, D. L.; Ambrose, S. H.; Bassett, T. J.; Bowen, M. L.; Crummey, D. E.; Isaacson, J. S.; Johnson, D. «Meanings of Environmental Terms». Journal of Environmental Quality26 (3): 581-589. ISSN0047-2425. doi:10.2134/jeq1997.00472425002600030002x.
«Archived copy». Archivado desde el original el 14 de julio de 2012. Consultado el 15 de julio de 2012.. The Columbia Encyclopedia. 2002. Nueva York: Columbia University Press
«Archived copy». Archivado desde el original el 14 de julio de 2012. Consultado el 15 de julio de 2012.. The Columbia Encyclopedia. 2002. Nueva York: Columbia University Press