[1] C. De Mitri and C. Guido, Some remarks on fuzzy powerset operators, Fuzzy Sets and Systems
126 (2002), 241-251.
[2] G. File, and F. Ranzato, Improving Abstract Interpretations by Systematic Lifting to the
Powerset, Proceedings of the 1994 International Symposium on Logic programming, MIT
Press Cambridge, MA, USA (1994), 655{669.
[3] A. Frascella and C. Guido, Transporting many-valued sets along many-valued relations, Fuzzy
Sets and Systems 159(1) (2008), 1-22.
[4] A. Frascella and C. Guido, Structured lattices and ground categories of L-sets, Int. J. Math.
and Math. Sci. 17 (2005), 2783-2803.
[5] G. Georgescu and A. Popescu, Non-dual fuzzy connections, Archive Math. Logic 43 (2004),
1009-1039.
[6] G. Gerla and L. Scarpati, Extension principles for fuzzy set theory, Journal of Information
Sciences 106 (1998), 49{69.
[7] H. Herrlich and C. G. Strecker, Category Theory, Sigma Ser. Pure Math. Vol. 1, Heldermann,
Berlin, 1979.
[8] U. Hohle, Fuzzy sets and sheaves. Part I, Basic concepts, Fuzzy Sets and Systems 158 (2007),
1143{1174.
[9] E. G. Manes, Algebraic Theories, Springer-Verlag, Berlin, New York, 1976.
[10] E. G. Manes, A class of fuzzy theories, Journal of mathematical Analysis and Applications,
(85) (1982), 409{451.
[11] J. Mockor, Extensional subobjects in categories of
-fuzzy sets, Czech.Math.J. 57(132)
(2007), 631{645.
[12] J. Mockor, Morphisms in categories of sets with similarity relations, Proceedings of IFSA
Congress/EUSFLAT Conference. Lisabon (2009), 560{568.
[13] J. Mockor, Cut systems in sets with similarity relations, Fuzzy Sets and Systems, (161)
(2010), 3127{3140.
[14] J. Mockor, Fuzzy sets and cut systems in a category of sets with similarity relations, Soft
Computing 16 (2012), 101{107.
[15] H. T. Nguyen, A note on the extension principle for Fuzzy sets, J. Math. Anal. Appl., 64
(1978), 369{380.
[16] V. Novak and I. Perfi lijeva and J. Mockor, Mathematical Principles of Fuzzy Logic , Kluwer
Academic Publishers, Boston, Dordrecht, London, 1999.
[17] S. E. Rodabaugh, Powerset operator based foundation for point-set lattice theoretic (poslat)
fuzzy set theories and topologies, Quaestiones Mathematicae 20(3) (1997), 463{530.
[18] S. E. Rodabaugh, Relationship of Algebraic Theories to Powerset Theories and Fuzzy Topo-
logical Theories for Lattice-Valued Mathematics, International Journal of Mathermatics and
Mathematical Sciences, (2007), 1{71.
[19] S. E. Rodabaugh, Relationship of algebraic theories to powersets over objects in Set and
Set C, Fuzzy Sets and Systems, 161(3) (2010), 453{470.
[20] K. I. Rosenthal, Quantales and Their Applications , Pittman Res. Notes in Math. 234, Longman,
Burnt Mill, Harlow, 1990.
[21] S. A. Solovyov, Powerset operator foundations for catalc fuzzy set theories, Iranian Journal
of Fuzzy Systems 8(2) (2011), 1{46.
[22] R. R. Yager, A characterization of the extension principle, Fuzzy Sets and Systems, 18
(1996), 205{217.
[23] L. A. Zadeh, Fuzzy sets, Information and Control, 8 (1965), 338{353.
)