Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

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

Citatione MLA (9a ed.)

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