[3] HU Q. P.-LI X.: 
On proper DCH-algebras. Math. Japon. 30 (1985), 659-661. 
MR 0812016[4] IMAI Y.-ISÉKI K.: 
On axiom systems of propositional calculi XIV. Proc. Japan Academy 42 (1966), 19-22. 
MR 0195704 | 
Zbl 0156.24812[5] ISÉKI K.: 
An algebra related with a propositional calculus. Proc. Japan Academy 42 (1966), 26-29. 
MR 0202571 | 
Zbl 0207.29304[7] JUN Y. B.-NEGGERS J.-KIM H. S.: 
Fuzzy d-ideals of d-algebras. J. Fuzzy Math. 8 (2000), 123-130. 
MR 1750234 | 
Zbl 0979.06012[10] NEGGERS J.-JUN Y. B.-KIM H. S.: 
On d-ideals in d-algebras. Math. Slovaca 49 (1999), 243-251. 
MR 1728235 | 
Zbl 0960.06010