Heydari, M., Xiaohu, Z., Lai, K.K., Yuxi, Z. and Chen, L. 2019. INVESTIGATING THE IMPACT OF CRISIS ON CORPORATE COSTS AND SALES USING ECONOMETRICS METHOD. Proceedings of National Aviation University. 81, 4 (Dec. 2019), 71–85. DOI:https://doi.org/10.18372/2306-1472.81.14604.