Yermagambet Bolat Toleukhanuly, Kazankapova Maira Kuttybaevna, Kassenova Zhanar Muratbekovna, и Nauryzbaeva Asemay Turlangyzy. «OBTAINING DERIVATIVES OF HUMIC SUBSTANCES FROM OXIDIZED COAL AND STUDY OF PHYSICO-CHEMICAL AND ADSORPTION PROPERTIES». Academic Scientific Journal of Chemistry, вып. 6, декабрь 2020 г., сс. 57-64, http://89.250.84.46/chemistry-technology/article/view/566.