1. Modern global climate change;Karl;Science,2003
2. Regional production and utilization of biomass in Sweden;Börjesson;Energy,1996
3. International energy outlook;USDOE Energy Information Administration,2009
4. Renewable Fuel Association. Climate of opportunity [monograph on the internet]. Washington: 2010 [cited 2010 Nov 13]. Available from: http://www.ethanolrfa.org/pages/annual-industry-outlook.
5. U.S. Grains Council. A guide to distillers dried grains with solubles [monograph on the internet]. Washington: 2007 [cited 2010 Oct 22]. Available from:http://www.grains.org/ddgs-information/217-ddgs-user-handbook.