Extension of additive functionals and semicharacters on commutative semigroups. P. Kranz — 1979 Semigroup forum
Additive functionals on abelian semigroups P. Kranz — 1972 Commentationes Mathematicae The article contains no abstract
Sandwich and extension theorems on semigroups and lattices P. Kranz — 1975 Commentationes Mathematicae The article contains no abstract