Shukurova Maftuna Davlat qizi. “IKKI NOMALUMLI CHIZIQLI INTEGRAL TENGLAMALAR SISTEMASI YECHIMLARINING MAVJUDLIK SHARTLARI”. Journal of New Century Innovations, vol. 27, no. 5, Apr. 2023, pp. 141-4, https://newjournal.org/new/article/view/5735.