private function _writeStringRecord($stringValue)
	{
		$record = 0x0207;	 // Record identifier
		$data = PHPExcel_Shared_String::UTF8toBIFF8UnicodeLong($stringValue);

		$length = strlen($data);
		$header = pack('vv', $record, $length);

		$this->_append($header . $data);
	}