Шамрай, В. І., and В. В. Коробийчук. “Influence of Grinding-Polishing of Natural Stone on Its Shine and Lightness Shades”. Eastern-European Journal of Enterprise Technologies, vol. 5, no. 5(71), Oct. 2014, pp. 56-60, doi:10.15587/1729-4061.2014.28036.