Sadaf M, Jabbar A. Measuring Sustainable Development through Eco-efficiency: A Case Study of Mega Cities of Pakistan. Pak. J. Econ. Stud. [Internet]. 2020 Dec. 31 [cited 2024 Apr. 23];3(2):105-22. Available from: https://journals.iub.edu.pk/index.php/pjes/article/view/384