public Ref3DPtg(CellReference c, int externIdx) {super(c);setExternSheetIndex(externIdx);}

public Ref3DPtg ( CellReference c , int externIdx ) { super ( c ) ; setExternSheetIndex ( externIdx ) ; }
public Ref3DPtg(CellReference cr, int externIdx):base(cr){ExternSheetIndex = externIdx;}
