- International energy statistics (US Energy Information Administration)
- Sustainable energy: without the hot air (chapter 1, page 5; David JC MacKay)
- BP statistical review of world energy 2011 (PDF, pages 6, 20, 30; BP)
- World energy demand and economic outlook (US Energy Information Administration)
- International energy outlook 2011 – highlights (US Energy Information Administration)
- 2010 survey of energy resources (PDF, pages 160, 161, 211; World Energy Council)
- Supply of uranium (World Nuclear Association)
- Types of renewable energy (Renewable Energy World)
- Sustainable energy: without the hot air (appendix B, page 264; David JC MacKay)
- Sustainable energy: without the hot air (chapter 6, page 39; David JC MacKay)