APA

Wollstadt R. D., American Petroleum Institute A. & Wollstadt R. D. (1983). Oil exploration in less developed countries. Washington: American Petroleum Institute, API.

Chicago

Wollstadt Roger D, American Petroleum Institute API and Wollstadt Roger D. 1983. Oil exploration in less developed countries. Washington: American Petroleum Institute, API.

Harvard

Wollstadt R. D., American Petroleum Institute A. and Wollstadt R. D. (1983). Oil exploration in less developed countries. Washington: American Petroleum Institute, API.

MLA

Wollstadt Roger D, American Petroleum Institute API and Wollstadt Roger D. Oil exploration in less developed countries. Washington: American Petroleum Institute, API. 1983.