Comments on the definition of a Tikhonov semifield homomorphism Papp, F.J. — 1978 Portugaliae mathematica
The functional equation f(xy) = ff(x) xy ff(y) in a partially ordered monoid. F.J. Papp — 1976 Aequationes mathematicae
The Functional Equation f(xy) = ff(x) xyff(y) in a Partially Ordered Monoid. (Short Communication). F.J. Papp — 1975 Aequationes mathematicae