Was a paper not not co-authored by Vasilios Stefanis and A. Komninos?
Didn't Vasilios S. and A. Komninos not co-author a paper?
ASK { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/88/2098> . ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/61/5974> }
<https://dblp.org/pid/88/2098> <https://dblp.org/pid/61/5974>