80 (2002) Establishment of a 3.83‐Ga magmatic age for the Akilia tonalite (southern West Greenland). Earth Planet. Sci. Lett. 202, 563‐576 doi:10.1016/S0012-821X(02)00825-7. [pdf] summary
3 (1996) Evidence for life on Earth before 3,800 million years ago. Nature 384, 55‐59 doi:10.1038/384055a0. [pdf] summary