D. Dinh-Cong, P. Nguyen-Huynh, S.-N. Nguyen, and T. Nguyen-Thoi, “Damage Identification of Functionally Graded Beams using Modal Flexibility Sensitivity-based Damage Index”, Period. Polytech. Civil Eng., vol. 67, no. 1, pp. 272–281, Jan. 2023.