A note on peripherally problems in the theory of compact semitopological monoids. W. Ruppert — 1981 Semigroup forum
On joint continuity in semigroups on compact manifolds with boundary. W. Ruppert — 1984 Semigroup forum
No semi topological monoid can be defined on the closure of the set { (x,sin 1 x) : xeR {o... W. Ruppert — 1981 Semigroup forum
In a left-topological semigroup with dense center the closure of any left ideal is an ideal. W. Ruppert — 1987 Semigroup forum
A separately, but not jointly continuous action of a compact semilattice. W. Ruppert — 1984 Semigroup forum
The structure of semitopological monoids defined on compact connected 3-manifolds. W. Ruppert — 1980 Semigroup forum
Complete systems of addition laws on Abelian varieties. H. Lange; W. Ruppert — 1985 Inventiones mathematicae
On a construction connecting Lie algebras with general algebras Michor, Peter W.; Ruppert, W.; Wegenkittl, K. — 1989 Proceedings of the Winter School "Geometry and Physics"