1. Zadeh , L.A., Fuzzy Sets, Information and Control, 8, 338-353, 1965.
2. Klir, G. J. & Folger, T. A., Fuzzy Sets, Uncertainty and Information, Prentice-Hall, London, 1988.
3. Voskoglou, M. Gr., Finite Markov Chain and Fuzzy Logic Assessment Models: Emerging Research and Opportunities, Columbia, SC, Createspace.com – Amazon, 2017.