Grimaldo Guerrero, John William, et al. “Analysis of the Energetic and Productive Effects Derived by the Installation of a Conveyor Belt in the Metal-Mechanic Industry”. International Journal of Energy Economics and Policy, vol. 8, no. 6, Oct. 2018, pp. 196-01, https://econjournals.com./index.php/ijeep/article/view/7066.