C. D. Viet, N. T. Nga, D. D. . Tho, T. V. D. Ngoc, N. V. . Dung, and L. H. Bac, “Structural, electrical and ferroelectric properties of NiTiO3 synthesized by citrate-gel method”, Vietnam J. Sci. Technol., vol. 60, no. 2, pp. 245–256, Mar. 2022.