What are the papers that Mathias Philipp and R. S. Sandhu published?
List all the papers that Mathias P. and Ravi S. Sandhu published.
SELECT DISTINCT ?answer WHERE { { ?answer <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/28/2124> } UNION { ?answer <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/s/RaviSSandhu> } }
<https://dblp.org/pid/28/2124> <https://dblp.org/pid/s/RaviSSandhu>