Ciupek, Bartosz, Rafał Urbaniak, and Karolina Perz. “Analysis of Technical Parameters of Black Coals Used in low?Power Boilers”. AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, no. 12 (December 31, 2018): 386–389. Accessed June 1, 2024. https://journals.economic-research.pl/atest/article/view/1254.