1.Ban Đoàn V, Tuấn TC, Thắng Đoàn V. Approximate answers to null queries with incomplete fuzzy information in object oriented database. J. Comput. Sci. Cybern. [Internet]. 2012 May 3 [cited 2025 Nov. 4];27(4):329-40. Available from: https://jcc.vast.vn/jcc/article/view/597