Special publication. (1980). Proceedings of symposium on drilling technology and engineering aids to geoogical exploration calcutta 12th to 15th february 1980: Special publication No.4. Geological Survey of India.
Trích dẫn kiểu ChicagoSpecial publication. Proceedings of Symposium on Drilling Technology and Engineering Aids to Geoogical Exploration Calcutta 12th to 15th February 1980: Special Publication No.4. Newdelhi: Geological Survey of India, 1980.
Trích dẫn MLASpecial publication. Proceedings of Symposium on Drilling Technology and Engineering Aids to Geoogical Exploration Calcutta 12th to 15th February 1980: Special Publication No.4. Geological Survey of India, 1980.
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