internal IfcDocumentReference(DatabaseIfc db, IfcDocumentReference r) : base(db,r) { mDescription = r.mDescription; if(r.mReferencedDocument > 0) ReferencedDocument = db.Factory.Duplicate(r.ReferencedDocument) as IfcDocumentInformation; } public IfcDocumentReference(DatabaseIfc db) : base(db) { }