The renewable sources of energy in the EU. 

Buchan, D. (2009): Energy and Climate Change: Europe at the Crossroads, 137-151.

Buchan, D.; Keay, M. (2015): Europe´s Long Energy Journey: Towards an Energy Union? 73-79, 84-100. 

IEA (2014): European Union – 2014 Review. IEA, 227-249.