On the simultaneous associativity of F(x, y) and x+y-F(x, y). (Short Communication). M.J. Frank — 1978 Aequationes mathematicae
Associativity in a Class of Operations on Spaces of Distribution Functions. M.J. Frank — 1975 Aequationes mathematicae
Associativity in a Class of Operations on Spaces of Distribution Functions. (Short Communication). M.J. Frank — 1974 Aequationes mathematicae
On the simultaneous associativity of F(x, y) and x + y - F(x, y). M.J. Frank — 1979 Aequationes mathematicae