@ARTICLE{Wierzchowski_Krzysztof_Variability_2017, author={Wierzchowski, Krzysztof and Chećko, Jarosław and Pyka, Ireneusz}, number={No 4}, journal={Archives of Mining Sciences}, howpublished={online}, year={2017}, publisher={Committee of Mining PAS}, title={Variability of Mercury Content in Coal Matter From Coal Seams of The Upper Silesia Coal Basin}, URL={http://www.journals.pan.pl/Content/105617/PDF/10267-Volume62_Issue4-11_paper.pdf}, doi={10.1515/amsc-2017-0058}, }