[4] Celani, S.: 
$\alpha$-ideals and $\alpha$-deductive systems in bounded Hilbert algebras. J. Mult.-{}Valued Logic and Soft Computing 21 (2013), 493-510. 
MR 3242515 | 
Zbl 06930415 
[8] Chajda, I., Halaš, R.: 
An example of a congruence distributive variety having no near-unanimity term. Acta Univ. M. Belii, Ser. Math. 13 (2006), 29-31. 
MR 2353310 | 
Zbl 1132.08002 
[9] Chajda, I., Halaš, R., Kühr, J.: 
Semilattice Structures. Research and Exposition in Mathematics 30. Heldermann, Lemgo (2007). 
MR 2326262 | 
Zbl 1117.06001 
[10] Chajda, I., Kolařík, M.: 
Ideals, congruences and annihilators on nearlattices. Acta Univ. Palacki. Olomuc., Fac. Rerum Nat., Math. 46 (2007), 25-33. 
MR 2387490 | 
Zbl 1147.06002