Muhammad Ali Iqbal, Muhammad Tariq Majeed, and Tania Luni, “Human Capital, Trade Openness and CO2 Emissions: Evidence from Heterogeneous Income Groups”, JESPK, vol. 15, no. 3, pp. 559–585, Sep. 2021, Accessed: Jun. 27, 2026. [Online]. Available: https://jes.ac.pk/index.php/jes/article/view/133