APA

Parra A., Petróleos de Venezuela P., World Petroleum Congress (11th. : 1983 : London) & Petróleos de Venezuela P.A view of the world petroleum supply and demand outlook. : .

Chicago

Parra A.A, Petróleos de Venezuela PDVSA, World Petroleum Congress (11th. : 1983 : London) and Petróleos de Venezuela PDVSA.A view of the world petroleum supply and demand outlook. : .

Harvard

Parra A., Petróleos de Venezuela P., World Petroleum Congress (11th. : 1983 : London) and Petróleos de Venezuela P.A view of the world petroleum supply and demand outlook. : .

MLA

Parra A.A, Petróleos de Venezuela PDVSA, World Petroleum Congress (11th. : 1983 : London) and Petróleos de Venezuela PDVSA.: . .