[1] Burris S.: Closure homomorphism. J. Algebra 15 (1970), 68-71. MR 0253961

[2] Chajda I., Zelinka B.: Compatible relations on algebras. Čas. pěst. matem. 100 (1975), 355-360. MR 0389710 | Zbl 0315.08004

[3] Chajda I.: Two constructions of compatible relations. Czech. Math. J. 28 (1978), 439-444. MR 0485621 | Zbl 0399.08003

[4] Chajda I.: Relational classes and their characterizations. Arch. Math. (Brno), 16 (1980), 199-204. MR 0594466 | Zbl 0449.08002

[5] Chvalina J.: Set transformations with centralizers formed by closed deformations of quasi-discerte topological spaces. Proc. Fourth Prague Top. Sym. 1976, Part B, Soc. Czech. Math. Phys. Prague 1977, 83-89. MR 0500872

[6] Grätzer G.: Universal Algebra. D. van Nostrand, New York 1968. MR 0248066

[7] Grimeisen G.: Continuous relations. Math. Zeit. 127 (1972), 35-44. MR 0312460 | Zbl 0224.54017

[8] Jónsson B.: Topics in Universal Algebra. Lect. Notes Math. 250, Berlin, Sprinfer 1972. MR 0345895

[9] Smithson R. E.: Multifunctions. Niew Arch. Wisk. 20 (1972). 31-55. MR 0305338 | Zbl 0238.54047

[10] Varlet J. C.: Endomorphisms and fully invariant congruences in unary algebras $\langle A;\Gamma \rangle$. Bull. Soc. Roy. Sci. Liège 39 (1970), 575-589. MR 0279023 | Zbl 0212.34901