@proceedings{sgem2013bd4,
  title = {13th International Multidisciplinary Scientific GeoConference SGEM 2013, Energy and Clean Technologies, Vol. 13, Book 4},
  author = {International authors},
  year = {2013},
  publisher = {STEF92 Technology},
  isbn = {},
  doi = {10.5593/sgem2013/bd4}
}