Gaya APA

Leffler, W, L. (2010). Petroleum refining in nontechnical language 10 : Hydrogen, hydrotreating, and sulfur plants, review (4). New York: PennWell B.

Gaya MLA

Leffler, William, L.. "Petroleum refining in nontechnical language 10 : Hydrogen, hydrotreating, and sulfur plants, review". 4 New York: PennWell B, 2010. Multimedia.