@article {6003,
	title = {Molybdenum isotope evidence for mild environmental oxygenation before the Great Oxidation Event},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {74},
	year = {2010},
	pages = {6655-6668},
	author = {Y. Duan and A.D. Anbar and G.L. Arnold and T.W. Lyons and G.W. Gordon and B. Kendall}
}