TIAN, Yuhao. Optimizing Educational Investment Efficiency in Upper Middle-Income Countries: Evidence from Five Emerging Economies. Highlights in Business, Economics and Management, [S. l.], v. 65, p. 400–409, 2025. DOI: 10.54097/e5tgxz04. Disponível em: https://hbemdata.org/index.php/ojs/article/view/62. Acesso em: 24 may. 2026.