@inproceedings{sgem2019s02059,
  title = {ROLE OF COAL LAYERS FOR THE FORMATION OF CHEMICAL COMPOSITION OF THE UPPER PONTIAN AQUIFER, NORTHWEST BULGARIA},
  author = {Aglaida Toteva},
  booktitle = {SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 19th SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings19th, Science and Technologies in Geology, Exploration And Mining},
  year = {2019},
  pages = {461-468},
  publisher = {STEF92 Technology},
  doi = {10.5593/sgem2019/1.2/s02.059}
}