https://qooah.com/2011/05/19/vodafone-%e6%8e%a8%e5%87%ba%e8%87%aa%e5%ae%b6%e5%93%81%e7%89%8c%e7%9a%84%e6%89%8b%e6%a9%9f-%ef%bc%8d-smart/