Παραπομπή APA

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.

Παραπομπή Chicago Style

Special 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.

Παραπομπή MLA

Special 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.