[1] S. Burris, H. P. Sankappanavar: A Course in Universal Algebra. Springer, New York, 1981. MR 0648287

[2] M. D. Gerhardts: Schrägverbände und Quasiordnungen. Math. Ann. 181 (1969), 65–73. DOI 10.1007/BF01351180 | MR 0241328 | Zbl 0175.01403

[3] M. D. Gerhardts: Zerlegungshomomorphismen in Schrägverbänden. Arch. Math. 21 (1970), 116–122. DOI 10.1007/BF01220889 | MR 0265231 | Zbl 0199.32201

[4] E. Graczyńska: On the sums of double systems of some universal algebras. Bull. de L’Acad. Polon. Sci. Math. Astronom. Phys. 23 (1975), 509–513. MR 0392752

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

[6] A. Haviar: N-Schrägverbände und Quasiordungen. Matematický časopis 23 (1973), 240–248. MR 0327592

[7] T. Hecht: Constructions of non-commutative algebras. Lectures in Universal Algebra (eds. L. Szabó, A. Szendrei), North-Holland, Amsterdam (1986), 177–187. MR 0860264 | Zbl 0597.08011

[8] J. Leech: Recent developments in the theory of skew lattices. Semigroup Forum 53 (1996), 7–24. MR 1363525 | Zbl 0844.06003

[9] J. Plonka: On a method of construction of abstract algebras. Fund. Math. 61 (1967), 183–189. DOI 10.4064/fm-61-2-183-189 | MR 0225701 | Zbl 0168.26701

[10] J. Plonka: Representations of algebras from varieties defined by some regular identities with nullary opertion symbols. Algebra Universalis 33 (1995), 441–457. DOI 10.1007/BF01225467 | MR 1331910

[11] V. Slavík: On skew lattices I. Comment. Math. Univ. Carolin. 14 (1973), 73–85. MR 0319829

[12] V. Slavík: On skew lattices II. Comment. Math. Univ. Carolin. 14 (1973), 493–506. MR 0344169

[13] M. Yamada, N. Kimura: Note on idempotent semigroups II. Proc. Japan. Acad. 34 (1958), 110–112. DOI 10.3792/pja/1195524790 | MR 0098141