Niedźwiedzki, Robert, Dawid Surmik, Agnieszka Chećko, and Mariusz A Salamon. “A Regurgitalite of the Middle Triassic (Muschelkalk) from Upper Silesia (Poland)”. Geology, Geophysics and Environment 47, no. 1 (April 28, 2021): 33–40. Accessed April 12, 2025. https://journals.agh.edu.pl/geol/article/view/4114.