[1] M. A. ARBIB E. G. MANES: 
Fuzzy morphisms in automata theory, in: Category Theory applied to Computation and. Control. Proc. of the 1st Internat. Symp., University of Massachusetts at Amherst, 1974, 98-105. 
MR 0403839[3] E. ČECH: 
Point Sets. Academia, Prague 1969. 
MR 0256344[4] S. EILENBERG G. M. KELLY: 
Closed Categories. in: Proc. Conf. on Categorial Algebra, La Jolla 1956 (Springer-Verlag 1966), 421-562. 
MR 0225841[6] A. PULTR: Closed categories of fuzzy sets. to appear in Proceedings of the conference "Automaten- und Algorithmen-theorie", Weissig, 1975.