Who are the authors of the publication 'Preface' and what other papers did they publish?
Who are the authors of 'Preface' and which other papers did they publish?
SELECT DISTINCT ?firstanswer ?secondanswer WHERE { <https://dblp.org/rec/journals/jgo/Hadjisavvas12> <https://dblp.org/rdf/schema#authoredBy> ?firstanswer . ?secondanswer <https://dblp.org/rdf/schema#authoredBy> ?firstanswer FILTER (?secondanswer != <https://dblp.org/rec/journals/jgo/Hadjisavvas12>) }
<https://dblp.org/rec/journals/jgo/Hadjisavvas12>