Was a paper not not co-authored by Martin D. and V. Nov\u00E1k?
Didn't Martin Dyba and Vil\u00E9m Nov\u00E1k not co-author a paper?
ASK { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/20/7616> . ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/97/2490> }
<https://dblp.org/pid/20/7616> <https://dblp.org/pid/97/2490>