Was a paper not not co-authored by Christine L. Lisetti and Piotr J. Gmytrasiewicz?
Didn't Christine L. Lisetti and Piotr J. Gmytrasiewicz not co-author a paper?
ASK { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/91/1021> . ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/50/887> }
<https://dblp.org/pid/91/1021> <https://dblp.org/pid/50/887>