Syahril, Muh. Akbar Fhad, and Hamida Hasan. “A Comparative Research on the Effectiveness of Progressive Versus Proportional Tax Systems in Enhancing Social Justice”. Administrative and Environmental Law Review 5, no. 2 (October 11, 2024): 97–106. Accessed September 5, 2025. https://jurnal.fh.unila.ac.id/index.php/aelr/article/view/3479.