Eugen-Laurentiu Niculici. "LITOLOGY, CHEMISTRY AND PHYSICAL PROPERTIES OF THE ROCKS IN THE DACIAN AND PONTIAN COAL-BEARING FORMATIONS OF THE EASTERN AREA OF THE DACIAN BASIN.." SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 19th SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings19th, Science and Technologies in Geology, Exploration And Mining, 2019, pp. 295-302. https://doi.org/10.5593/sgem2019/1.1/s01.036