1. G. Czédli, A Mal'cev type condition for te semi-distributivity of congruence lattices,Acta Sci. Math. (Szeged),43 (1981), 267–272.
2. G. Czédli, A characterization for congruence semi-distributivity,Universal Algebra and Lattice Theory (Proceedings, Puebla, 1982), Springer-Verlag Lecture Notes in Math, 1004 (Berlin-Heidelberg-New York-Tokyo, 1983), 104–110.
3. G. Czédli and A. Day, Horn sentences with (W) and weak Mal'cev conditions,Algebra Universalis, submitted.
4. J. Hagemann,Mal'cev conditions for algebraic relations, preprint (1973).
5. J. Hagemann and A. Mitschke, Onn-permutable congruences,Algebra Universalis,3 (1973), 8–12.