Didn't Samuel Sch\u00FCppen and P. Herrmann not co-author a paper?
Was a paper not not co-authored by Sch\u00FCppen, Samuel and P. Herrmann?
ASK { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/197/8073> . ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/133/5020> }
<https://dblp.org/pid/197/8073> <https://dblp.org/pid/133/5020>