Why not simply Google?
Ahmet Soylu, Martin A. Giese, Ernesto Jiménez-Ruiz, Evgeny Kharlamov, Dmitriy Zheleznyakov, Ian Horrocks · 2014
We demonstrate an ontology-based visual query system, namely OptiqueVQS, for end users without any technical background to formulate rather complex information needs into formal queries over databases. It is built on multiple and coordinated representation and interaction paradigms and a flexible widget-based architecture.