Cal, B. (2004). Pinoy invents "super" anti-pollution device. Manila Bulletin.
Cita Chicago (17th ed.)Cal, Ben. "Pinoy Invents "Super" Anti-pollution Device." Manila Bulletin 2004.
Cita MLA (9th ed.)Cal, Ben. "Pinoy Invents "Super" Anti-pollution Device." Manila Bulletin, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.