Fonseca Vigoya, Marlen, et al. “Analysis of the Level of Implementation of Programs for the Efficient Use of Energy and Unconventional Sources: Case Study Colombia”. International Journal of Energy Economics and Policy, vol. 10, no. 5, Aug. 2020, pp. 679-86, https://econjournals.org.tr/index.php/ijeep/article/view/9713.