Johnson, R. B., & Degraff, V. J. (1988). Principles of Engineering Geology. John Wiley.
Čikaški stil citiranjaJohnson, Robert. B., i V. Jerome Degraff. Principles of Engineering Geology. New Delhi: John Wiley, 1988.
MLA način citiranjaJohnson, Robert. B., i V. Jerome Degraff. Principles of Engineering Geology. John Wiley, 1988.
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