Dai, Feng, Jingxu Liu, and Ling Liang. “Industry Segmentation under Environmental Pressure: An Optimal Approach”. Technological and Economic Development of Economy 19, no. 1 (January 28, 2014): S524-S543. Accessed December 2, 2024. https://aviation.vgtu.lt/index.php/TEDE/article/view/4342.