1. United Nations (UN), The Millennium Development Goals Report 2015 (2015) ISBN 978-92-1-101320-7.
2. B. M.-L. Brigitte Baptiste, Review of Targets for the Sustainable Development Goals: The Science Perspective (2015) ISBN: 978-0-930357-97-9.
3. Wikipedia, Energy (2017) Available: https://en.wikipedia.org/wiki/Energy [Accessed: 01-Mar-2017].
4. A new energy security paradigm for the twenty-first century
5. Groen gas: gas van aardgaskwaliteit vit biomasssa: update van de studie vit;Welink,2007