R.M.Tolipov and M.S.Xusanova (2024) “BOSHLANG’ICH SINF MATEMATIKA DARSLARIDA KOMBINATORIKA MASALALARI USTIDA ISHLASH”, University Research Base, pp. 179–181. Available at: https://scholar.kokanduni.uz/index.php/rb/article/view/627 (Accessed: 5 December 2025).