Pulatov А. M., and N. N. o‘g‘li Karimov. “IKKI O‘LCHOVLI MURAKKAB SOHANI O‘ZARO QO‘SHISH”. Educational Research in Universal Sciences, vol. 2, no. 2, Feb. 2023, pp. 71-78, http://erus.uz/index.php/er/article/view/1689.