[1] G. Grätzer J. Plonka A. Sekanina:
On the number of polynomials of a universal algebra I. Coll. Math. XXII (1970), 9-11.
MR 0294216
[3] M. Sekanina:
Number of polynomials in ordered algebras. Coll. Math. XXII (1971), 181 to 192.
MR 0282905 |
Zbl 0233.06006
[4] K. Urbaník:
On algebraic operations in idempotent algebras. Coll. Math. XIII (1965), 129-157.
MR 0179119