Chau Dinh Thanh, Le Viet Tuan, Nguyen Van Hieu, and Goangseup Zi. “Phantom Node Method for Arbitrarily Craked Problems With 4-Node Quadrilateral Elements”. Journal of Technical Education Science, vol. 9, no. 3, Sept. 2014, pp. 55-62, https://www.jte.edu.vn/index.php/jte/article/view/557.