{"id":"001351577","type":"book","title":"The origin of castles in the eastern part of the Delta Region (NL/D) and the rise of the principalities of Guelders and Cleves","publisher":"CRAHM","publisher-place":"Caen","pages":"3-16","container-title":"Études de castellogie médiévale","author":[{"family":"Aarts","given":"B."}],"issued":{"raw":"2012"}}