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^ a b c Espen Aas (2017) – Vi har funnet verdens eldste form for liv. Urix (web), NRK, 1. mars 2017. Besøkt 2017-03-01
^ Cavalier-Smith, T. (2004): Only six kingdoms of life. The Royal Society PDF.
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^ Thomas Cavalier-Smith. (2004). Only six kingdoms of life. Proc. R. Soc. Lond. B 2004 271, 1251-126. doi: 10.1098/rspb.2004.2705. Besøkt 6. november 2011
^ Rybicki, E.B. (1990). «The classification of organisms at the edge of life, or problems with virus systematics». South Africal Journal of Science. 86: 182–186. Besøkt 24. april 2016.
^ In Warm, Greasy Puddles, the Spark of Life?
^ Scharf, C. (2014). «Is Earth’s Life Unique in the Universe?». Scientiffic American.
^ Rosen, J. «Scientists may have found the earliest evidence of life on Earth». Science. Besøkt 24. april 2016.
^ Borenstein, Seth (19. oktober 2015). «Hints of life on what was thought to be desolate early Earth». Excite. Yonkers, NY: Mindspark Interactive Network. Associated Press. Arkivert fra originalen 23. oktober 2015. Besøkt 20. oktober 2015.
^ Croswell, Ken (februar 1996). Alchemy of the Heavens. Anchor. ISBN 0-385-47214-5.