M. C. Abounaima, L. Lamrini, N. E. Makhfi, and M. Ouzarf "Comparison by Correlation Metric the TOPSIS and ELECTRE II Multi-Criteria Decision Aid Methods: Application to the Environmental Preservation in the European Union Countries", Advances in Science, Technology and Engineering Systems Journal, vol. 5, no. 5, pp. 1064–1074, 2020, doi: 10.25046/aj0505131.