Gaya APA
Keller, Edward A.. (1999).
Introduction to environmental geology .
Upper Saddle River, NJ:
Prentice Hall.
Gaya Chicago
Keller, Edward A..
Introduction to environmental geology.
Upper Saddle River, NJ:
Prentice Hall,
1999.
Text.
Gaya MLA
Keller, Edward A..
Introduction to environmental geology.
Upper Saddle River, NJ:
Prentice Hall,
1999.
Text.
Gaya Turabian
Keller, Edward A..
Introduction to environmental geology.
Upper Saddle River, NJ:
Prentice Hall,
1999.
Print.