1. Use of economic instruments in the Germany renewable electricity policy;Agnolucci;Energy Policy,2006
2. Arnold Cassola, Per Gahrton (Eds.), 2003. Twenty Years of European Greens 1984–2004. 〈http://www.globalgreens.info/literature/books/20years/contents.html〉.
3. Policies and market factors driving wind power development in the United States;Bird;Energy Policy,2005
4. Green Parties and Politics in the European Union;Bomberg,1998
5. Business News, 2008. Small-business forum objects to Eskom price hike. Johannesburg South Africa. 〈http://www.mg.co.za/articlepage.aspx?area=/breaking_news/breaking_news__business/&articleid=337526〉.