@article{D._Knez_Looking_2018,
 author={D. Knez and Calicki, A.},
 volume={66},
 number={No 1},
 howpublished={online},
 journal={Bulletin of the Polish Academy of Sciences: Technical Sciences},
 pages={3-8},
 year={2018},
 title={Looking for a new source of natural proppants in Poland},
 type={Artykuły / Articles},
 doi={10.24425/119052},
 keywords={proppant, mechanical properties, hydraulic fracturing},
}