Chrzan, Tadeusz, and Henryk Greinert. “CONCEPTIONS OF LAND RECLAMATION IN THE POLISH OPENCAST MINING”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 27, 1997): 26–34. Accessed April 27, 2024. https://journals.rta.lv/index.php/ETR/article/view/1856.