1. Delgado, M., Vila, M.A., Voxman, W.: On a canonical representation of fuzzy numbers. Fuzzy Sets Syst. 93, 125–135 (1998)
2. Dubois, D., Prade, H.: Operations on fuzzy numbers. Int. J. Syst. Sci. 9, 613–629 (1978). https://doi.org/10.1080/00207727808941724
3. Klir, G.J.: Developments in uncertainty-based information. Adv. Comput. 36, 255–332 (1993). https://doi.org/10.1016/s0065-2458(08)60273-9
4. Kosiński, W.: On fuzzy number calculus. Int. J. Appl. Math. Comput. Sci. 16(1), 51–57 (2006)
5. Kosiński, W., Prokopowicz, P., Ślęzak, D.: Drawback of fuzzy arithmetics – new intuitions and propositions. In: Burczyński, T., Cholewa, W., Moczulski, W. (eds.) Methods of Artificial Intelligence, Gliwice, pp 231–237 (2002)