1. Regional electricity markets in Europe: focus on the energy community;Karova;Util Policy,2011
2. Integration of electricity markets in Europe: relevant issues for Italy;Creti;Energy Policy,2010
3. Evaluation of economic, energy-environmental and sociological effects of substituting non-renewable energy with renewable energy sources;Kozioł;JSDEWES,2015
4. Worldmeters. www.worldometers.info/world-population/population-by-country/ [accessed October 3, 2015].
5. European Commission – Eurostat. ec.europa.eu/eurostat/statistics-explained/index.php/Population_structure_and_ageing [accessed February 26, 2016].