Antonio, T. (1997). Duty-free shops illegal? Manila Bulletin.
Cita Chicago (17th ed.)Antonio, Tony. "Duty-free Shops Illegal?" Manila Bulletin 1997.
Cita MLA (9th ed.)Antonio, Tony. "Duty-free Shops Illegal?" Manila Bulletin, 1997.
Atenció: Aquestes cites poden no estar 100% correctes.