Didn't M. Yamada and Kikuchi, Hiroaki not co-author a paper?
Was a paper not not co-authored by M. Yamada and Kikuchi, Hiroaki?
ASK { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/25/2929> . ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/90/4508> }
<https://dblp.org/pid/25/2929> <https://dblp.org/pid/90/4508>