DOKTOR, Marek, and Andrzej J. KRAWCZYK. “The Model of Entropy for the Upper Carboniferous Coal-Bearing Formations in the Upper Silesian Coal Basin and an Attempt of Its Geological Interpretation”. Geology, Geophysics and Environment 36, no. 1 (January 1, 2010): 37. Accessed January 18, 2025. https://ggae.agh.edu.pl/index.php/geol/article/view/292.