Lu, Changyuan, Hexiang Zhu, Yuan Yao, Xueyu Nian, and Xiyuan Fan. “Analysis of the Mask Price Change from the Perspective of Economics”. Financial Forum 9, no. 4 (January 28, 2021): 185-190. Accessed November 24, 2024. https://ojs.piscomed.com/index.php/FF/article/view/1531.