Cita APA (7th ed.)

Keller, E. A. (1999). Introduction to environmental geology. Prentice-Hall, Inc.

Cita Chicago (17th ed.)

Keller, Edward A. Introduction to Environmental Geology. Upper Saddle River, New Jersey: Prentice-Hall, Inc, 1999.

Cita MLA (9th ed.)

Keller, Edward A. Introduction to Environmental Geology. Prentice-Hall, Inc, 1999.