Karlis Cerans Guntis Barzdins Renars Liepins Julija Ovcinnikova Sergejs Rikacovs Arturs Sprogis Graphical Schema Editing for Stardog OWL/RDF Databases using OWLGrEd/S. 2012 OWLED http://ceur-ws.org/Vol-849/paper_19.pdf conf/owled/2012 db/conf/owled/owled2012.html#CeransBLORS12