Investment Efficiency in Indonesia’s Construction Sub-Sector: An Optimal Portfolio Approach Using the Markowitz Model. Jurnal Ilmu Keuangan dan Perbankan (JIKA), [S. l.], v. 14, n. 1, p. 177–190, 2025. DOI: 10.34010/jika.v14i1.15149. Disponível em: https://ojs.unikom.ac.id/index.php/jika/article/view/15149. Acesso em: 19 apr. 2025.