@inproceedings{sgem2017s17082,
  title = {ULTRA CLEAN COAL FROM POLISH COAL DEPOSITS},
  author = {Andrzej Slaczka and Adam Wasilczyk},
  booktitle = {SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies},
  year = {2017},
  pages = {659-666},
  publisher = {STEF92 Technology},
  doi = {10.5593/sgem2017/42/s17.082}
}