1. J. Aczél. Lectures on Functional Equations and their Applications. Academic Press. New York. (1966).
2. C. Alsina and E. Trillas. “Synthesizing Implications”. International Journal of Intelligent Systems 7 (1992) 705–713.
3. B. De Baets and R. Mesiar, “Pseudo-metrics and T-equivalences”. J. Fuzzy Math, Vol. 5, No. 2 (1997) 471–481.
4. D. Dubois and H. Prade. “Aggregation of possibility measures”, in Multiperson Decision Making Using Fuzzy Sets and Possibility Theory, J. Kacprzyk, M. Fedrizzi (eds), Kluwer Academic Publishers. (1990).
5. E. Klement, R. Mesiar and E. Pap. Triangular Norms. Kluwer Academic Publisher. (2000).