Maria Lazar. CONSIDERATIONS ON THE INFLUENCE OF EXTRACTION TECHNOLOGY OF LIGNITE IN OPEN PITS OVER THE PRODUCTION QUALITY. SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; SGEM2012 12th International Multidisciplinary Scientific GeoConference, 2012. https://doi.org/10.5593/sgem2012/s03.v1013