(2013). State of the World 2013 (1.). Island Press/Center for Resource Economics.
Cita Chicago (17th ed.)State of the World 2013. 1. Island Press/Center for Resource Economics, 2013.
Cita MLA (8th ed.)State of the World 2013. 1. Island Press/Center for Resource Economics, 2013.
Atenció: Aquestes cites poden no estar 100% correctes.