Niedźwiedzki, R.; Surmik, D.; Chećko, A.; Salamon, M. A. A Regurgitalite of the Middle Triassic (Muschelkalk) from Upper Silesia (Poland). geol 2021, 47 (1), 33-40. https://doi.org/10.7494/geol.2021.47.1.33.