Muhammad Ali Iqbal, Muhammad Tariq Majeed and Tania Luni (2021) “Human Capital, Trade Openness and CO2 Emissions: Evidence from Heterogeneous Income Groups”, Pakistan Journal of Commerce and Social Sciences, 15(3), pp. 559–585. Available at: https://jes.ac.pk/index.php/jes/article/view/133 (Accessed: 27 June 2026).