Gaya APA
CUNNINGHAM, W, P. et al (2003).
Environmental Science : A Global Concern - Seventh Edition .
New York:
Mc Graw Hill Book Company.
Gaya MLA
CUNNINGHAM, William, P.. et al.
"Environmental Science : A Global Concern - Seventh Edition".
New York:
Mc Graw Hill Book Company,
2003.
Text.