Aigars Kokins. "EVALUATION OF LIMONITE CONCRETIONS BY CHEMICAL AND MINERALOGICAL COMPOSITION, THEIR FORMATION MODEL.." SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 18th International Multidisciplinary Scientific GeoConference SGEM2018, Science and Technologies in Geology, Exploration and Mining, 2018, pp. 91-98. https://doi.org/10.5593/sgem2018/1.1/s01.012