CSA - Fuel Cell Overviewhttp://www.csa.com/discoveryguides/fuecel/overview.phpUS Department of Energy - Fuel Cell Handbookhttp://www.netl.doe.gov/technologies/coalpower/fuelcells/seca/pubs/FCHandbook7.pdfNational Energy Technology Laboratory - Solid State Energy Conversion Alliancehttp://www.netl.doe.gov/technologies/coalpower/fuelcells/seca/National Geographic - The Green Guide - Household Carbon Footprint Calculatorhttp://www.thegreenguide.com/doc/119/calculator