Lechman, M., and P.M. Lewiński. “Generalized Section Model for Analysis of Reinforced Concrete Chimney Weakened by Openings”. Engineering Transactions 49, no. 1 (June 26, 2015): 3–28. Accessed June 9, 2025. https://et3.ippt.pan.pl/index.php/et/article/view/571.