@inproceedings{sgem2019s03041,
  title = {HARD COAL RESOURCES IN THE UPPER SILESIA COAL BASIN (POLAND) ACCORDING TO POLISH CLASSIFICATION AND INTERNATIONAL JORC CODE},
  author = {Jarosław Chećko},
  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 = {323-330},
  publisher = {STEF92 Technology},
  doi = {10.5593/sgem2019/1.3/s03.041}
}