@article {6017,
	title = {Redox conditions across the Cambrian-Ordovician boundary: elemental and isotopic signatures retained in the GSSP carbonates},
	journal = {Palaeogeography, Palaeoclimatology, Palaeoecology},
	volume = {440},
	year = {2015},
	pages = {440-454},
	author = {K. Azmy and B. Kendall and U. Brand and S. Stouge and G.W. Gordon}
}
