Hoang Lan-Ton That, Thanh Chau-Dinh, and Nguyen Van Hieu. “Improvement on Six-Node Triangular Finite Element (IT6) Using Twice-Interpolation Strategy for Linear Elastic Fracture Mechanics”. Journal of Technical Education Science, vol. 14, no. 2, Apr. 2019, pp. 32-40, https://www.jte.edu.vn/index.php/jte/article/view/214.