http://www.aktors.org/ontology/portal#has-URL

used by 8:

• rkb-explorer-budapest
• rkb-explorer-curriculum
• rkb-explorer-deepblue
• rkb-explorer-deploy
• rkb-explorer-ibm
• rkb-explorer-irit
• rkb-explorer-pisa
• rkb-explorer-ulm