SHAPOVAL Світлана, FOROSTIANA Нінель, and RASULOV Раміс. 2013. “xpress ethods of tudying utter omposition”. "INTERNATIONAL·SCIENTIFIC-·PRACTICAL·JOURNAL·COMMODITIES·AND·MARKETS" 15 (1):43-52. https://journals.knute.edu.ua/commodities-and-markets/article/view/1318.