Krupnova, T.; Rakova, O. .; Udachin, V. .; Gavrilkina, S.; Bondarenko, K. . ISOTOPIC RATIOS AS A TOOL FOR STUDYING SOURCES OF COPPER, LEAD, AND ZINC IN NATURAL AND URBAN ENVIRONMENTS: A REVIEW. INTERNATIONAL JOURNAL OF GEOMATE 2023, 25, 33-41.