De França, J. A.; Carvalho, N. A.; Pereira, C. C.; Vieira, E. T. . The Operational Sustainability of the Firm : The Operational Performance Versus Financial Solvency Binomial - OPFS . Int J Innov Educ Res 2021, 9 (1), 353-370. https://doi.org/10.31686/ijier.vol9.iss1.2909.