ZHUKOVA, Y., P. PETROV, and L. KLIMENKO. “xpress ethod of uantitative etermination of rea in ilk”. NTERNATIONAL CIENTIFIC-RACTICAL OURNAL OMMODITIES ND ARKETS, vol. 24, no. 2, Dec. 2017, pp. 17-35, https://journals.knute.edu.ua/commodities-and-markets/article/view/1151.