Gaya APA
Leffler, W, L.
(2009).
Petroleum refining in nontechnical language 8 : Gasoline
(
4)
.
New York:
PennWell B.
Gaya MLA
Leffler, William, L..
"Petroleum refining in nontechnical language 8 : Gasoline".
4
New York:
PennWell B,
2009.
Multimedia.