Artyukh, T., G. Kupalova, V. Bazylevych, I. Hryhorenko, and A. Ternova. “Improving a Procedure for Determining the Assay of Gold in a Precious Alloy of Different Composition Using a Touchstone”. Eastern-European Journal of Enterprise Technologies, vol. 2, no. 12 (98), Apr. 2019, pp. 6-19, doi:10.15587/1729-4061.2019.165408.