Nv. Hoa, TO THE DESCRIPTION OF CLOSED CLASSES PRES ERVED BY ALL INNER AUTOMORPHISMS OF KAPPA-VALUED LOGIC, Doklady Akademii nauk BSSR, 38(3), 1994, pp. 16-19
The structure description of all closed classes preserved by all inner
automorphisms of k-valued logic and without constant is given for k g
reater-than-or-equal-to 4,