1. K. Atanassov, Intuitionistic Fuzzy Sets, VII ITKR Session, Sofia (Deposed in Centr. Sci.-Techn. Library of Bulg. Acad. of Sci., 1697/84), 1983 (in Bulgarian).
2. Intuitionistic Fuzzy Sets: Theory and Applications;Atanassov,1999
3. On Intuitionistic Fuzzy Sets Theory;Atanassov,2012
4. K. Atanassov, V. Tasseva, E. Szmidt, J. Kacprzyk, On the geometrical interpretations of the intuitionistic fuzzy sets, in: K. Atanassov, J. Kacprzyk, M. Krawczak, E. Szmidt (Eds.), Issues in the Representation and Processing of Uncertain and Imprecise Information. Fuzzy Sets, Intuitionistic Fuzzy Sets, Generalized Nets, and Related Topics, EXIT, Warsaw, 2005.
5. H. Bustince, V. Mohedano, E. Barrenechea, M. Pagola, An algorithm for calculating the threshold of an image representing uncertainty through A-IFSs, in: IPMU’2006, 2006, pp. 2383–2390.