D, Altantsetseg, Batjargal B, Otgonbaatar D, and Bolorchimeg G. 2022. “Estimation of the Regression Equation Based on the Pulp Density by ‘AR-31-M’ XRF Spectrometer”. Scientific Transaction of the National University of Mongolia. Physics 20 (438):45-50. https://doi.org/10.22353/physics.v20i438.123.