Cita APA (7a ed.)

Herrera, A. (1999). Highly active absorbent for SO2 removal prepared from coal ash (Part 3). Philippine Engineering Journal.

Cita Chicago Style (17a ed.)

Herrera, A.B. "Highly Active Absorbent for SO2 Removal Prepared from Coal Ash (Part 3)." Philippine Engineering Journal 1999.

Cita MLA (9a ed.)

Herrera, A.B. "Highly Active Absorbent for SO2 Removal Prepared from Coal Ash (Part 3)." Philippine Engineering Journal, 1999.