APA Citatie

Johnson, R. B., & Degraff, V. J. (1988). Principles of Engineering Geology. John Wiley.

Chicago Style citaat

Johnson, Robert. B., en V. Jerome Degraff. Principles of Engineering Geology. New Delhi: John Wiley, 1988.

MLA citatie

Johnson, Robert. B., en V. Jerome Degraff. Principles of Engineering Geology. John Wiley, 1988.