-''Yale Environment 360'', 2011<ref>''Yale Environment 360'' (2011, May 17). "[http://featured.matternetwork.com/2011/5/ancient-ocean-sediments-show-mass.cfm Ancient Ocean Sediments Show Mass Die-Offs in Eras of High CO2]."</ref>}} | -''Yale Environment 360'', 2011<ref>''Yale Environment 360'' (2011, May 17). "[http://featured.matternetwork.com/2011/5/ancient-ocean-sediments-show-mass.cfm Ancient Ocean Sediments Show Mass Die-Offs in Eras of High CO2]."</ref>}} |