Li, Yancang, Yang Peng, and Shujing Zhou. “Improved PSO Algorithm for Shape and Sizing Optimization of Truss Structure”. Journal of Civil Engineering and Management 19, no. 4 (September 2, 2013): 542-549. Accessed November 14, 2019. https://journals.vgtu.lt/index.php/JCEM/article/view/3882.