1. Burmeister, P.: A Model Theoretic Oriented Approach to Partial Algebras. Introduction to Theory and Application of Partial Algebras. Part I, Mathematical Research, vol. 32. Akademie-Verlag, Berlin (1986)
2. Mlitz, R. (ed.): General algebra. In: Proc. Internat. Conf. Krems 1988, North Holland, Amsterdam (1990)
3. Grätzer, G.: Universal Algebra, 2nd edn. Springer, New York (1979)
4. Jakubík, J.: On convexities of lattices. Czechoslov. Math. J. 42(117), 325–330 (1992)
5. Jakubíková-Studenovská, D.: Convex subsets of partial monounary algebras. Czechoslov. Math. J. 38(113), 655–672 (1988)