APA

Mathis J. F., Exxon, World Petroleum Congress (10th : 1979 sept. 9-14 : Bucharest) & Exxon.Intensified use of petroleum and natural gas for petrochemicals. : .

Chicago

Mathis James F, Exxon, World Petroleum Congress (10th : 1979 sept. 9-14 : Bucharest) and Exxon.Intensified use of petroleum and natural gas for petrochemicals. : .

Harvard

Mathis J. F., Exxon, World Petroleum Congress (10th : 1979 sept. 9-14 : Bucharest) and Exxon.Intensified use of petroleum and natural gas for petrochemicals. : .

MLA

Mathis James F, Exxon, World Petroleum Congress (10th : 1979 sept. 9-14 : Bucharest) and Exxon.: . .