On the relationship between projective distributive lattices and Boolean algebras. Ploščica, M. (1994) Acta Mathematica Universitatis Comenianae. New Series
On von Neumann varieties. Borceux, F., Rosický, J. (2004) Theory and Applications of Categories [electronic only]
One-element extensions in the variety generated by tournaments Jaroslav Ježek (2004) Czechoslovak Mathematical Journal We investigate congruences in one-element extensions of algebras in the variety generated by tournaments.