APA

World Petroleum Congress (7th : 1967 abr. 2-8 : México), . (1968). Seventh world petroleum congress. New York: Elsevier Publishing Company.

Chicago

World Petroleum Congress (7th : 1967 abr. 2-8 : México), . 1968. Seventh world petroleum congress. New York: Elsevier Publishing Company.

Harvard

World Petroleum Congress (7th : 1967 abr. 2-8 : México), . (1968). Seventh world petroleum congress. New York: Elsevier Publishing Company.

MLA

World Petroleum Congress (7th : 1967 abr. 2-8 : México), . Seventh world petroleum congress. New York: Elsevier Publishing Company. 1968.