Khôi, L.H., Hồng, Đặng X. and Đống, N.L. 2012. Some problems about Archimedean Triangular norms. Journal of Computer Science and Cybernetics. 20, 4 (Aug. 2012), 373–383. DOI:https://doi.org/10.15625/1813-9663/20/4/1906.