Perroni, Marcos, Luciano Luiz Dalazen, Wesley Vieira Da Silva, Sergio Gouvêa, and Claudimar Pereira Da Veiga. 2015. “Evolution of Risks for Energy Companies from the Energy Efficiency Perspective: The Brazilian Case”. International Journal of Energy Economics and Policy 5 (2):612-23. https://econjournals.com./index.php/ijeep/article/view/1058.