एपीए उद्धरण

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

शिकागो स्टाइल उद्धरण

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

एमएलए उद्धरण

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