@proceedings{sgem202041,
  title = {20th International Multidisciplinary Scientific GeoConference SGEM 2020, Energy and Clean Technologies, Vol. 20, Issue 4.1},
  author = {International authors},
  year = {2020},
  publisher = {STEF92 Technology},
  isbn = {},
  doi = {10.5593/sgem2020/4.1}
}