@inproceedings{sgem2008paper,
  title = {QUARTZ (GLASS) SAND - THE BASIC RAW MATERIAL FOR GLASS-MAKING},
  author = {A. Grinc and J. Mikulenka and I. Petrovs},
  booktitle = {8th International Scientific Conference - SGEM2008},
  year = {2008},
  pages = {513-516},
  publisher = {SGEM Scientific GeoConference},
  doi = {}
}