Singh, B., Goel, R. K., & Goel, R. K. (1999). Rock mass classification: A practical approach in civil engineering. Amsterdam New York: Elsevier.
Παραπομπή Chicago StyleSingh, Bhawani, R. K. Goel, and R. K. Goel. Rock Mass Classification: A Practical Approach in Civil Engineering. Amsterdam New York: Elsevier, 1999.
Παραπομπή MLASingh, Bhawani, R. K. Goel, and R. K. Goel. Rock Mass Classification: A Practical Approach in Civil Engineering. Amsterdam New York: Elsevier, 1999.
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