Tursunboy Abdullo o’g’li Qobilov. “IKKINCHI TARTIBLI CHIZIQLI XUSUSIY HOSILALI DIFFERENSIAL TENGLAMALARNI TIPINI ANIQLASH”. Diversity Research: Journal of Analysis and Trends, vol. 1, no. 3, June 2023, pp. 277-83, http://academiaone.org/index.php/2/article/view/141.