[1] P. Crawley and R. P. Dilworth: Algebraic Theory of Lattices, Prentice Hall, Englewood Cliffs. New Jersey, (1973).

[2] H. Draškovičová: Weak direct product decomposition of algebras, in: Contributions to General Algebra 5, Proc. of Salzburg Conf. 1986. Verlag Holder-Pichler-Tempsky, Wien (1987), 105–121. MR 0930914

[3] G. Grätzer: General Lattice Theory. Akademie-Verlag, Berlin, 1978. MR 0504338

[4] G. Grätzer: Universal Algebra. Springer-Verlag, New York, 1979. MR 0538623

[5] J Hashimoto: Direct, subdirect decompositions and congruence relations. Osaka Math. J. 9 (1957), 87–112. MR 0091248 | Zbl 0078.01805

[6] T. K. Hu: Weak products of simple universal algebras. Math. Nachr. 42 (1969), 157–171. DOI 10.1002/mana.19690420111 | MR 0258714 | Zbl 0207.02901

[7] R. McKenzie, G. McNulty and W. Taylor: Algebras, Lattices, Varieties, Volume I, Wadsworth Brooks/Cole. Menterey-California, 1987. MR 0883644

[8] A. Walendziak: Infinite $\theta $-decomposition in modular lattices, in: Universal and Applied Algebra, Proc. of Turawa Symposium 1988. Vorld Sci. Publishing, Teaneck, NJ, (1989), 321–333. MR 1084413

[9] A. Walendziak: Infinite $\theta $-decompositions in upper continuous lattices. Comment. Math 29 (1990), 313–324. MR 1059137 | Zbl 0719.06003

[10] A. Walendziak: L-restricted $\varphi $–representations of algebras. Period. Math. Hung 23 (1991), 219–226. DOI 10.1007/BF02278036 | MR 1152971

[11] A. Walendziak: Irredundant $\varphi $-representations of algebras—existence and some uniqueness. Algebra Universalis 30 (1993), 319–330. DOI 10.1007/BF01190440 | MR 1225871 | Zbl 0788.08002