%0 Journal Article %T Archaea in Past and Present Geobiochemical Processes and Elemental Cycles %A Michael Hoppert %A Martin Kr¨ąger %A Joachim Reitner %A Charles Cockell %J Archaea %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/930493 %U http://www.hindawi.com/journals/archaea/2013/930493/