. W. Victor Yossif, “Bowing Effect on Elastic Stability for Members Having Concave Configuration Shapes”, J. eng. sustain. dev., vol. 11, no. 3, pp. 167–193, Dec. 2007, Accessed: Jul. 05, 2025. [Online]. Available: https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1753