Gaya APA
KELLER, E, A., FOLCHETTI, N, [. (2008).
Introduction to environmental geology (4th ed.).
New Jersey:
Pearson.
Gaya MLA
KELLER, Edward, A.., FOLCHETTI, Nicole, [ed.].
"Introduction to environmental geology".
4th ed.
New Jersey:
Pearson,
2008.
Buku.