public Boundsheet[] getBoundSheets()
	{
		if( ptga == null )
		{
			try
			{
				initPtga();
			}
			catch( Exception e )
			{
				;
			}
		}
		if( ptga instanceof PtgRef3d )
		{
			PtgRef3d p3d = (PtgRef3d) ptga;
			Boundsheet b = p3d.getSheet( getWorkBook() );
			Boundsheet[] ret = new Boundsheet[1];
			ret[0] = b;
			return ret;
		}
		if( ptga instanceof PtgArea3d )
		{
			PtgArea3d p3d = (PtgArea3d) ptga;
			return p3d.getSheets( getWorkBook() );
		}
		if( ptga instanceof PtgMemFunc )
		{
			PtgMemFunc p = (PtgMemFunc) ptga;
			return p.getSheets( getWorkBook() );
		}
		return null;
	}