WYSOCKI, J. Analysis of the Energy Efficiency Operational Indicator in Economic and Ecological Aspect. Scientific Journal of Gdynia Maritime University, [S. l.], n. 100, p. 200–213, 2017. Disponível em: https://ojs.umg.edu.pl/index.php/sjgmu/article/view/190. Acesso em: 18 may. 2024.