@inproceedings{sgem201941,
  title = {19th International Multidisciplinary Scientific GeoConference SGEM 2019, Energy and Clean Technologies, Vol. 19, Issue 4.1},
  author = {International authors},
  booktitle = {International Multidisciplinary Scientific GeoConference SGEM 2019},
  year = {2019},
  pages = {},
  publisher = {STEF92 Technology},
  doi = {10.5593/sgem2019/4.1}
}