Dreger, Marcin. “Changes in the Methane Emissions and Hard Coal Output in the Brzeszcze Mine (the Upper Silesian Coal Basin, Poland)”. Geology, Geophysics and Environment 46, no. 2 (October 16, 2020): 159. Accessed November 13, 2024. https://ggae.agh.edu.pl/index.php/geol/article/view/3722.