Gasparyan, V.M., et al. “ECOLOGICAL SIGNIFICANCE OF LITHOGEOCHEMICAL EXPLORATION METHODS FOR ORE DEPOSITS”. Proceedings of the YSU C: Geological and Geographical Sciences, vol. 47, no. 1 (230), Apr. 2013, pp. 3-9, doi:10.46991/PYSU:C/2013.47.1.003.